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Real Number Part 1 - Lecture 1
Real numbers
Any number that we can think of in the real world is a real number . set of real number is denoted by R. real numbers include natural numbers (N) , whole numbers (W), Integers (Z/I), rational numbers (Q) and irrational numbers (R-Q) .
For example:-
1,3.5,√7,3.¯2,22/7,π,1.234 etc
are real numbers .
In this chapter we also learn about LCM and HCF
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20min
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Real Number Part 2 - Lecture 2
Real numbers
Any number that we can think of in the real world is a real number . set of real number is denoted by R. real numbers include natural numbers (N) , whole numbers (W), Integers (Z/I), rational numbers (Q) and irrational numbers (R-Q) .
For example:-
1,3.5,√7,3.¯2,22/7,π,1.234 etc
are real numbers .
In this chapter we also learn about LCM and HCF
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24min
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Real Number Part 3 - Lecture 3
Real numbers
Any number that we can think of in the real world is a real number . set of real number is denoted by R. real numbers include natural numbers (N) , whole numbers (W), Integers (Z/I), rational numbers (Q) and irrational numbers (R-Q) .
For example:-
1,3.5,√7,3.¯2,22/7,π,1.234 etc
are real numbers .
In this chapter we also learn about LCM and HCF
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39min
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HCF & LCM - Lecture 4
LCM and HCF
LEAST COMMON MULTIPLE (LCM)
COMMON MULTIPLE :- A common multiple of two numbers is a number which is exactly divisible by each of given numbers .
e.g. 45 is a common multiple of 3,5,9,15
LEAST COMMON MULTIPLE :- The least common multiple of two or given numbers is the least number which is exactly divisible by each one of them .
e.g.12 is common multiple of 2,3,4 & 24 is also common multiple of 2,3,4 but 12 is LCM of 2,3,4
HIGHEST COMMON FACTOR (HCF)
Highest common factor is also known as greatest common divisor (GCD)
COMMON FACTOR :-
A common factor of two or more numbers is a number which divides each of them exactly .
e.g. 3 is a common factor of 3,12,18
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48min
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Simplification Part 1 - Lecture 5
SIMPLIFICATION
Simplification is a process of reducing a complex expression into a simpler form.
‘VBODMAS’ Rule
This rule gives the correct order in which various operations regarding simplification are to be performed, so as to find out the values of given expressions in simple ways. Let us see what these letters mean. Order of operations is as same as the order of letters in the ‘VBODMAS’ from the left to right as
V B O D M A S
Left to right
Clearly, the order will be as follows
First Vinculum bracket is solved,
(Remember – 6 – 8 = - 14 but – 6- 8 = - (-2) = 2)
Second Brackets are to be solved in order given below
• First, small brackets (circular brackets ) ‘( )’
• Second , middle brackets (curly brackets) ‘{ }’
• Third , square brackets (big brackets) ‘[ ]’
Third Operation of ‘Of’ is performed.
Fourth Operation of division is performed.
Fifth Operation of multiplication is performed.
Sixth Operation of addition is performed.
Seventh Operation of subtraction is performed
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26min
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BODMAS Simplification Part 2 - Lecture 6
SIMPLIFICATION
Simplification is a process of reducing a complex expression into a simpler form.
‘VBODMAS’ Rule
This rule gives the correct order in which various operations regarding simplification are to be performed, so as to find out the values of given expressions in simple ways. Let us see what these letters mean. Order of operations is as same as the order of letters in the ‘VBODMAS’ from the left to right as
V B O D M A S
Left to right
Clearly, the order will be as follows
First Vinculum bracket is solved,
(Remember – 6 – 8 = - 14 but – 6- 8 = - (-2) = 2)
Second Brackets are to be solved in order given below
• First, small brackets (circular brackets ) ‘( )’
• Second , middle brackets (curly brackets) ‘{ }’
• Third , square brackets (big brackets) ‘[ ]’
Third Operation of ‘Of’ is performed.
Fourth Operation of division is performed.
Fifth Operation of multiplication is performed.
Sixth Operation of addition is performed.
Seventh Operation of subtraction is performed
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22min
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Surd & Indices Simplification Part 3 - Lecture 7
SIMPLIFICATION
Simplification is a process of reducing a complex expression into a simpler form.
‘VBODMAS’ Rule
This rule gives the correct order in which various operations regarding simplification are to be performed, so as to find out the values of given expressions in simple ways. Let us see what these letters mean. Order of operations is as same as the order of letters in the ‘VBODMAS’ from the left to right as
V B O D M A S
Left to right
Clearly, the order will be as follows
First Vinculum bracket is solved,
(Remember – 6 – 8 = - 14 but – 6- 8 = - (-2) = 2)
Second Brackets are to be solved in order given below
• First, small brackets (circular brackets ) ‘( )’
• Second , middle brackets (curly brackets) ‘{ }’
• Third , square brackets (big brackets) ‘[ ]’
Third Operation of ‘Of’ is performed.
Fourth Operation of division is performed.
Fifth Operation of multiplication is performed.
Sixth Operation of addition is performed.
Seventh Operation of subtraction is performed
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28min
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Percentage - Lecture 8
Percentage
Percent means per hundred. It is denoted by the symbol % .Here x% means x/100.Thus ,any percentage can be converted into an equivalent fraction by dividing it by 100.
Short Tricks
1. When a value/number/quantity 'A' is increased or decreased by b%, then new value/number/quantity will be
= (100 ±b)/100* A
2. If A is a% more than B, then b is less than a by [a/(100+a)* 100 ]%
3. If A is a % less than B, then b is more than a by [a/(100-a)* 100 ]%
4. When the value of an object is first changed (increased or decreased) by x% and then changed by y % then net effect is given as = [± x ±y + ((± x) (± y)))/100] % (+ ve sign indicates increase, - ve sign indicates decrease.)
5. If the price of a commodity increases or decreases by a%, then the decrease or increase in consumption so as not to increase or decrease the expenditure is equal to ( a/(100 ±a )) * 100%
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46min
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Ratio And Proportion - Lecture 9
Ratio
If a and b are two quantities of same kind, then a/b is known as the ratio of a and b . It is written as a:b.
The first of the ratio is called antecedent while the second term is called consequent.
e.g., Ratio between 30kg and 50kg is 3: 5.
Proportion
The equality of two ratios is called proportion a, b, c, d are said to be in proportion if a : b = c : d or a : b : : c : d. Here, ‘a’ is the first second term ‘c’ is the third term and ‘d’ is the fourth term. Here, first and fourth terms are called extremes i.e., a and d while the second and third terms are called as means i.e., b and c.
e.g., if 3 : 2 : : 135 : 90, then 3, 90 are the extremes while 2, 135 are called the means. In a proportion, we always have:
Product of extremes = product of means
a x d = b x c
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43min
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Mixture & Allegations - Lecture 10
Mixture
To determine the mean value of the mixture when the prices of the individual items being mixed together and the proportion in which they are being mixed are given. Here, the value of the mixture is always higher than the lowest value and lower than highest value of the items being mixed.
According to the Rule of Alligation, if two quantities are in a ratio, then
(Quantity of cheaper)/(Quantity of dearer) = (Cost price of dearer-Mean price)/(Mean price-Cost price of cheaper)
It can also be expressed as,
Cost price of 1 unit Cost price of 1 unit
quantity of cheaper (x) quantity of dearer (y)
Mean price (m)
(y-m) (m-x)
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36min
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Average - Lecture 11
AVERAGE
Average is the mean value of a set of numbers or values. Therefore average of a set of numbers is,
Average= (X_1+ X_2+ X_3+ ……..〖+ X〗_n)/n or in other words, Average of some observations = (Sum of all observations)/(Number of all observations)
Remarks:-
If each observation of the given data is increased by same quantity, say x, then their average also increases by x.
If each observation of the given data is decreased by same quantity, say x their then average also decreases by x.
If each observation of the given data is multiplied same quantity, say x then their average also multiplied by x.
If each observation of the given data is divided by same quantity, say, x then their average also divided by x.
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32min
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Time & Work - Lecture 12
In our daily life, we have to complete different kinds of work in different stipulated time and if we are not able to complete the work in definite time,we arrange some more persons for it.Different persons have different abilities to do work.
Basic Rules
1. If time taken by a person to complete a work in x days,then work done in 1day is 1/x
2. If a person can do 1/x part in 1day , then he completes that work in x days
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42min
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Clock - Lecture 13
Clock
A clock has two hands, the smaller one is called the hour hand or short hand while the larger one is called the minute hand or long hand.
The face of a clock is a circular dial which subtends an angle of 360° at the centre. The circumference of the dial is divided into 12 equal parts to be called hour spaces. Every hour space is further divided into 5 equal parts to be called minute space. Hence, the total circumference is divided into 12 x 5= 60 equal minute space.
Fundas
In one hour, both the hands coincide once.
In one hour, the hands are straight (point in opposite directions) once.
In one hour, the hands are twice perpendicular to each other.
In 60 min, the minute hand covers 360°. Thus, in 1 min the minute hand covers (360/60)° = 6°
In 12 h, the hour hand covers 360°. Thus, in 1 min, the hour hand covers (360/(12*60))° = (1°)/2
Thus, in one minute, the minute hand gains ( 6 - 1/2) = 5 - 1/2, then the hour hand.
When the two hands are at right angles, they are 15 min spaces apart
When the two hands are in opposite directions, they are 30 min spaces apart
In 60 min, the minute hand gains 55 min on the hour hand.
The minute hand moves 12 times as fast as the hour hand.
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47min
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Calendar - Lecture 14
CALENDAR
ORDINARY YEAR -An ordinary year has 365 days
LEAP YEAR-Leap year has 366 days
(a)Any year (except a century) which is divisible by 4 is a leap year.
(b)Century is a leap year if it is divisible by 400
Example: 1924, 1964, 1660, 1880, 1808 are all leap years.
400, 800, 1200, 1600, 2000 are all leap years.
Total leap year /29 Feb in 100 years=24 Total leap year/29 Feb in 400 years=97
Total 29th Date in 100 years =1124 Total 29th Date in 400 years=4497
ODD DAYS - The number of days more than the complete weeks for a given period called odd days
HOW TO CALCULATE ODD DAYS FOR "n" NUMBER OF DAYS:
(a) Divide the number of days by 7.
(b) The remainder so obtained is the number of odd days
NUMBER OF ODD DAYS DAY OF THE WEEK
0 Sunday
1 Monday
2 Tuesday
3 Wednesday
4 Thursday
5 Friday
6 Saturday
NOTE
1ordinary year
=365 days
=(52 weeks +1day)
1ordinary year =1odd day 1leap year
=366days
=(52 weeks+2days)
1leap year=2 odd days
100years
=76 ordinary years +24 leap years
=(76*1+24*2)odd days
= 124 odd days
=(17weeks+5days) = 5 odd days 200 years
=( 5*2 =10 odd days)
= 1week +3 days = 3 odd days
300 years
=(5*3 = 15 odd days)
= 2weeks +1 day
= 1 odd day
400 years
= (5*4 +1 = 21 odd days)
= 3weeks +0 day
= 0 odd day
• Similarly, 800 year, 1200 year, 1600year, 2000year have 0 odd days
• Last day of the century may be Sunday, Monday, Wednesday, Friday
• Last day of the century cannot be Tuesday, Thursday, Saturday
• The day on which ordinary year begins it ends on its same day
Example: If 1st Jan 2001 was Monday then 31st Dec 2001 was also Monday
REPETITION OF SAME CALENDAR IN YEARS
IN CASE OF COMPLETE REPEAT
(a) Divide the Given Year by 4
(b) You will get one of the following remainders
1, 2, 3, 0
(c) Add the following years in the remainders:
Remainders Number of years to be added
1 6
2 11
3 11
0 28
IN CASE OF PARTIAL REPEAT
(a) Year will match only from January 1st to February 28.
(b) Ordinary year will match the Leap year and vice-versa.
*Number of odd days must be multiple of 7.
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39min
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Binary Number - Lecture 15
• Binary system: In the binary system, only two symbols 0 and 1 are used. Since, in this system only two numbers are used, so its base or radix is 2.
• Decimal system: in the decimal, we use 10 digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Since, 10 basic symbols are used in this system, so its base or radix 10.
In this chapter we will do;
1. Decimal to binary conversion
2. Binary to decimal conversion
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24min
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Profit and Loss - Lecture 16
Profit and loss and discount
Cost price (CP) the price at which an article is bought is called its cost price. All the overhead expenses in the transaction are added to the cost price .
Selling price (SP) The price at which an article is sold is Called the selling price.
Profit →if SP > CP then there is a profit
Profit = SP-CP & P% = (SP-CP)/CP × 100
LOSS → If CP > SP then there is a loss.
Loss = CP – SP & L% = (CP-SP)/CP × 100
MARKED PRICE OR LIST PRICE :- it is marked on the article
Discount :- The Reduction allowed on the marked price of an article is called as discount . discount is always calculated on marked price .
Discount = marked price – selling price
D% = (MP-SP)/MP × 100
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43min
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Simple Interest - Lecture 17
1. Principal: The money borrows or lend out for a certain period is called the principal or the sum.
2. Interest: Extra money paid for using other's money is called interest.
3. Simple Interest: If the interest on a sum borrowed for a certain period is reckoned uniformly, then it is called simple interest.
Let principal = P, Rate = R% per annum (p.a.) and Time = T year.
4. Compound interest : Someti¬mes borrower & the lender agree to fix up a certain units of time, say yearly or halfly or quarterly to settle the previous account. After a specified period, the difference between the amount and money is borrowed called the compound interest (C.I.) for that period.
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33min
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Compound Interest - Lecture 18
1. Principal: The money borrows or lend out for a certain period is called the principal or the sum.
2. Interest: Extra money paid for using other's money is called interest.
3. Simple Interest: If the interest on a sum borrowed for a certain period is reckoned uniformly, then it is called simple interest.
Let principal = P, Rate = R% per annum (p.a.) and Time = T year.
4. Compound interest : Someti¬mes borrower & the lender agree to fix up a certain units of time, say yearly or halfly or quarterly to settle the previous account. After a specified period, the difference between the amount and money is borrowed called the compound interest (C.I.) for that period.
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37min
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Measurement Area & Perimeter Part 1 - Lecture 19
Mensuration :- Mensuration is a branch of mathematical science that is concerned with the measurement of areas and volumes of various geometric figures . It is of two types
2D and 3D mensuration
2D Mensuration applies to two dimensional
figures like squares, rectangles, triangles, trapezium etc.
3D Mensuration applies to three dimensional figures like cube, cuboids, sphere, cone, cylinder etc.
Area: Total space inside the boundary of a plane figure is called the area of that particular figure. Area is measured in square Unit.
Perimeter:- It is the length of border around enclosed plane. Therefore, Sum of the sides of the a plane figure is the perimeter of that particular figure.
Volume: volume is the space occupied by an object
considering 3dimensional view.The formulas for calculating
Volume vary with the shape of the object. The units of volume
is cubic meters, cubic centimetre etc
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43min
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Measurement Area & Perimeter Part 2 - Lecture 20
Mensuration :- Mensuration is a branch of mathematical science that is concerned with the measurement of areas and volumes of various geometric figures . It is of two types
2D and 3D mensuration
2D Mensuration applies to two dimensional
figures like squares, rectangles, triangles, trapezium etc.
3D Mensuration applies to three dimensional figures like cube, cuboids, sphere, cone, cylinder etc.
Area: Total space inside the boundary of a plane figure is called the area of that particular figure. Area is measured in square Unit.
Perimeter:- It is the length of border around enclosed plane. Therefore, Sum of the sides of the a plane figure is the perimeter of that particular figure.
Volume: volume is the space occupied by an object
considering 3dimensional view.The formulas for calculating
Volume vary with the shape of the object. The units of volume
is cubic meters, cubic centimetre etc
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18min
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Volume & Surface Area Part 1 - Lecture 21
Mensuration :- Mensuration is a branch of mathematical science that is concerned with the measurement of areas and volumes of various geometric figures . It is of two types
2D and 3D mensuration
2D Mensuration applies to two dimensional
figures like squares, rectangles, triangles, trapezium etc.
3D Mensuration applies to three dimensional figures like cube, cuboids, sphere, cone, cylinder etc.
Area: Total space inside the boundary of a plane figure is called the area of that particular figure. Area is measured in square Unit.
Perimeter:- It is the length of border around enclosed plane. Therefore, Sum of the sides of the a plane figure is the perimeter of that particular figure.
Volume: volume is the space occupied by an object
considering 3dimensional view.The formulas for calculating
Volume vary with the shape of the object. The units of volume
is cubic meters, cubic centimetre etc
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40min
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Volume & Surface Area Part 2 - Lecture 22
Mensuration :- Mensuration is a branch of mathematical science that is concerned with the measurement of areas and volumes of various geometric figures . It is of two types
2D and 3D mensuration
2D Mensuration applies to two dimensional
figures like squares, rectangles, triangles, trapezium etc.
3D Mensuration applies to three dimensional figures like cube, cuboids, sphere, cone, cylinder etc.
Area: Total space inside the boundary of a plane figure is called the area of that particular figure. Area is measured in square Unit.
Perimeter:- It is the length of border around enclosed plane. Therefore, Sum of the sides of the a plane figure is the perimeter of that particular figure.
Volume: volume is the space occupied by an object
considering 3dimensional view.The formulas for calculating
Volume vary with the shape of the object. The units of volume
is cubic meters, cubic centimetre etc
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32min
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Volume & Surface Area Part 3 - Lecture 23
Mensuration :- Mensuration is a branch of mathematical science that is concerned with the measurement of areas and volumes of various geometric figures . It is of two types
2D and 3D mensuration
2D Mensuration applies to two dimensional
figures like squares, rectangles, triangles, trapezium etc.
3D Mensuration applies to three dimensional figures like cube, cuboids, sphere, cone, cylinder etc.
Area: Total space inside the boundary of a plane figure is called the area of that particular figure. Area is measured in square Unit.
Perimeter:- It is the length of border around enclosed plane. Therefore, Sum of the sides of the a plane figure is the perimeter of that particular figure.
Volume: volume is the space occupied by an object
considering 3dimensional view.The formulas for calculating
Volume vary with the shape of the object. The units of volume
is cubic meters, cubic centimetre etc
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23min
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Statistics - Lecture 24
Statistics is concerned with collection of data, presentation of data and analysis of data in the numerical form.
Collection of data involves collection of primary as well as secondary data.
Primary data is the data which is collected for the first time for statistical investigation.
Secondary data refers to the data which is already collected and used for current statistical investigation.
Measures of central tendency includes the measures of Mean, Median and Mode.
Mean also known as average is the sum of all the items divided by number of items.
Median refers to the middle number sorted ascending or descending.
Mode refers to the mostly appearing figure in the given series.
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55min
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Probability - Lecture 25
Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking, 0 indicates impossibility of the event and 1 indicates certainty. Probability is simply how likely something is to happen. Whenever we're unsure about the outcome of an event, we can talk about the probabilities of certain outcomes—how likely they are. The analysis of events governed by probability is called statistics.
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46min
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Time and Distance - Lecture 26
Time and distance
Speed
The distance travelled in a unit time is known as speed.
Speed = (distance travelled)/(Time Taken)
Units of speed are km/h, m/s etc.
To convert speed of an object from km/h to m/s, multiply the speed by 5/18 .
To convert speed of an object from m/s to km/h, multiply the speed by 18/5 .
Average speed
Average speed is the ratio of total distance covered to total time of journey.
Average speed = (Total distance covered)/(Total time of journey)
Rules for Solving Time and Distance Problems
Rule 1 If a certain distance is covered with a speed of ‘x’ km/h and another equal distance with a speed of ‘y’ km/h then the average speed for the whole journey is the harmonic mean of the two speeds
Average speed = (2xy/(x+y))km/h
(This formula is applicable only when the distance is constant)
Rule 2 If a certain distance is covered with a speeds of ‘x’ km/h and another distance with a speed of ‘y’ km/h but time interval for both journeys being same, then average speed for the whole journey is given by
Average speed = ((x+y)/2)km/h
Rule 3 If the ratio of speed A and B is x : y, then the ratio of time taken by them to cover the same distance is y : x.
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29min
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Boats & Stream - Lecture 27
Time and distance
Speed
The distance travelled in a unit time is known as speed.
Speed = (distance travelled)/(Time Taken)
Units of speed are km/h, m/s etc.
To convert speed of an object from km/h to m/s, multiply the speed by 5/18 .
To convert speed of an object from m/s to km/h, multiply the speed by 18/5 .
Average speed
Average speed is the ratio of total distance covered to total time of journey.
Average speed = (Total distance covered)/(Total time of journey)
Rules for Solving Time and Distance Problems
Rule 1 If a certain distance is covered with a speed of ‘x’ km/h and another equal distance with a speed of ‘y’ km/h then the average speed for the whole journey is the harmonic mean of the two speeds
Average speed = (2xy/(x+y))km/h
(This formula is applicable only when the distance is constant)
Rule 2 If a certain distance is covered with a speeds of ‘x’ km/h and another distance with a speed of ‘y’ km/h but time interval for both journeys being same, then average speed for the whole journey is given by
Average speed = ((x+y)/2)km/h
Rule 3 If the ratio of speed A and B is x : y, then the ratio of time taken by them to cover the same distance is y : x.
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33min
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Problem on Train - Lecture 28
Time and distance
Speed
The distance travelled in a unit time is known as speed.
Speed = (distance travelled)/(Time Taken)
Units of speed are km/h, m/s etc.
To convert speed of an object from km/h to m/s, multiply the speed by 5/18 .
To convert speed of an object from m/s to km/h, multiply the speed by 18/5 .
Average speed
Average speed is the ratio of total distance covered to total time of journey.
Average speed = (Total distance covered)/(Total time of journey)
Rules for Solving Time and Distance Problems
Rule 1 If a certain distance is covered with a speed of ‘x’ km/h and another equal distance with a speed of ‘y’ km/h then the average speed for the whole journey is the harmonic mean of the two speeds
Average speed = (2xy/(x+y))km/h
(This formula is applicable only when the distance is constant)
Rule 2 If a certain distance is covered with a speeds of ‘x’ km/h and another distance with a speed of ‘y’ km/h but time interval for both journeys being same, then average speed for the whole journey is given by
Average speed = ((x+y)/2)km/h
Rule 3 If the ratio of speed A and B is x : y, then the ratio of time taken by them to cover the same distance is y : x.
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32min
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Polynomial - Lecture 29
Polynomial
An expression in term of some variable(s) is called a polynomial.
f(x)=2x-5 is a polynomial in variable x
The expressions like 3x^2 –√(x,) 1/( x^2 7× +6) , 5x^3 - 4/x,etc., are not polynomials. Thus, a rational integral function of ‘x’ is said to be a polynomial, if the powers of ‘x’ in the terms of the polynomial are neither fractions nor negative. Thus, an expression of the form f (x) = a_n x^n + a_(n-1 ) x^(n-1) +……+ a_1x + a_o is called a polynomial in variable x where n be a positive integer anda_o, a_1, …….., a_n be constants ( real numbers).
Degree of a polynomial The exponent of the highest degree term in a polynomial is known as its degree.
e.g. , f(x) = 4x -3/2 is a polynomial in the variable x of degree 1.
Linear polynomial A polynomial of degree one is called a linear polynomial. In general, f(x) = ax + b, where a ≠0 is a linear polynomial.
Quadratic polynomial A polynomial of degree two is called a quadratic polynomial. In general, f (x) = 〖ax〗^(2 ) + bx + c, where a≠ 0 is a quadratic polynomial
e.g. , f(x) = x^2 – 7x + 8 is a trinomial as it contains 3 terms.
Cubic polynomial A polynomial of degree 3 is called a cubic polynomial in general
f (x) = 〖ax〗^3 + 〖bx〗^2 + cx + d, a ≠ 0 is a cubic polynomial.
f (x) = 〖2x〗^3 - x^(2 ) + 8x + 4
Biquadratic polynomial A fourth degree polynomial is called a biquadratic polynomial in general.
f (x) =〖ax〗^4 + 〖bx〗^3 + 〖cx〗^2 + dx + e, a ≠ 0 is a biquadratic polynomial.
Zero of a polynomial A real number ∝ is a zero (or root) of a polynomial
f (x), if f (∝) = 0
e.g., if x = 1 is a root of the polynomial 〖3x〗^3 - 〖2x〗^(2 )+ x – 2, then f (1) = 0
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36min
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Linear Equation - Lecture 30
Linear Equations when we equate two algebraic expressions using the signs of equality it forms an equation. Linear equations are first degree equations and may contain one or more variables. If the equation has only one variable, then the equation itself is sufficient to obtain the value of the variable. If the equation has two variables then two consistent equations are required to get the value of the variables. In general, an equation has n variables then n consistent equations are required to obtain all the value of the n variables.
Linear Equation in One Variable These are first degree equations in one unknown. An equation of the form ax + b = 0 where a, b ∈ R and a ≠ 0 and x is the variable, is called a linear equation in one variable. We have, only one variable x whose value we have to find out.
Linear Equation in two Variables These are first in two unknowns. An equation of the ax + by + c = 0, where a, b, c ∈ R and a ≠ 0, b ≠ 0 and x, y are variables is called linear equation in two variables have, two variables x and y whose values we have to find out.
Any pair of values of x and y which satisfy the equations ax + by + c = 0, is called its solution.
When two or more equations are satisfied by the same set values of the variables involved in them, then the termed as simultaneous equations.
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40min
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Quadratic Equation - Lecture 31
Quadratic Equation These are second degree equations of the form 〖ax〗^(2 ) + bx + c = 0, where a, b, c ∈ R and a ≠ 0 are quadratic equations.
Like a first degree equation in x has one value of x satisfying the equation, a quadratic equation in x will have two values of x that satisfy the equation. The value of x that satisfy the equation are called the roots of the equation. These roots may be real or imaginary.
x^(2 ) + 5x + 6 = 0 has roots x = -2,- 3
Using Formula If the quadratic is 〖ax〗^(2 )+ bx + c = 0, then we can use the standard formula given below to find out the roots of the equation. If α and β are the roots of the quadratic equation, then
∝=(-b+√(b^2-4ac))/2a and β=(-b-√(b^2-4ac))/2a
Sum and product of Roots of a Quadratic Equation
If ∝ and β are the roots of the quadratic equation 〖ax〗^(2 ) + bx + c = 0
Sum of the roots = ∝ + β = - b/a
Product of the roots = ∝β = c/a
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41min
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Trigonometry - Lecture 32
Trigonometric Ratios
The ratios between different sides of a right angled triangle w.r.t. its acute angles are called trigonometric ratios. Trigonometric ratios for right angled ∆ABC w.r.t angle A are given below.
sin A = BC/AC = P/H
cos A = AB/AC = B/H
tan A = BC/AB = P/B
cosec A = AC/BC = H/P
sec A = AC/AB = H/B
cot A =AB/BC =B/P
Relation between Trigonometric Ratios
sin A = 1/(cosec A) or cosec A = 1/sinA
cos A = 1/secA or sec A = 1/(cos A)
tan A = sinA/cos〖A 〗 or cot A = cosA/sinA
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52min
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Coordinate Geometry - Lecture 33
Quadrants
The axes X'OX and Y'OY divide the whole plane into four parts which are called quadrants. Here, OX and OX' are called the positive and negative directions respectively of x-axis and similarly OY and OY’ prime are the positive and negative directions, respectively of y-axis.
In 1st quadrant, x > 0, y > 0
In 2nd quadrant, x < 0 y > 0
In 3rd quadrant, x < 0 , y < 0
In 4th quadrant, x > 0, y < 0
The coordinates of any point on the x-axis are of the form (x, 0) and on the y-axis are of the form (0, y).If the x-coordinate or abscissa of a point is zero, then it would be somewhere on the y-axis and if its y-coordinate or ordinate is zero, then it would be on x-axis.
Distance Formulae
The distance between any two points is the length of the line segment joining them.
i.e. D = √(〖(x_2- x_1)〗^2+〖(y_2- y_1)〗^2 )
Or D = √(〖(Difference of bscissa)〗^2+ 〖(Difference of ordinates)〗^2 )
The distance between any two points is the length of the line segment joining them.
Section formula
Case I For external division
x=(〖mx〗_2- 〖nx〗_1)/(m-n),y= (〖my〗_2- 〖ny〗_1)/(m-n)
Case II For Internal division
x=(〖mx〗_2+ 〖nx〗_1)/(m+ n),y= (〖my〗_2+ 〖ny〗_1)/(m+n)
Area of Triangle
Let A (x_1 y_1), B (x_2 y_2) and C (x_3 y_3) be the coordinates of the vertices of ∆ABC.
Area of ∆ABC = 1/2 [x_1 (y_2- y_3 )+ x_2 (y_3- y_1 )+x_3 (y_1- y_2)]
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39min
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Height and Distance - Lecture 34
Trigonometric Ratios
The ratios between different sides of a right angled triangle w.r.t. its acute angles are called trigonometric ratios. Trigonometric ratios for right angled ∆ABC w.r.t angle A are given below.
sin A = BC/AC = P/H
cos A = AB/AC = B/H
tan A = BC/AB = P/B
cosec A = AC/BC = H/P
sec A = AC/AB = H/B
cot A =AB/BC =B/P
Relation between Trigonometric Ratios
sin A = 1/(cosec A) or cosec A = 1/sinA
cos A = 1/secA or sec A = 1/(cos A)
tan A = sinA/cos〖A 〗 or cot A = cosA/sinA
Trigonometric Ratios
The ratios between different sides of a right angled triangle w.r.t. its acute angles are called trigonometric ratios. Trigonometric ratios for right angled ∆ABC w.r.t angle A are given below.
sin A = BC/AC = P/H
cos A = AB/AC = B/H
tan A = BC/AB = P/B
cosec A = AC/BC = H/P
sec A = AC/AB = H/B
cot A =AB/BC =B/P
Relation between Trigonometric Ratios
sin A = 1/(cosec A) or cosec A = 1/sinA
cos A = 1/secA or sec A = 1/(cos A)
tan A = sinA/cos〖A 〗 or cot A = cosA/sinA
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50min
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Basic Geometry Part 1 - Lecture 35
GEOMETRY
Geometry is the most important topic of maths section in PSTET. Geometry can be defined as the study of shapes.
Plane Geometry is related to the properties and relation of plane figures, such as angles, triangles, other polygons and circles.
Line is defined by its length but has no breadth. A line contains infinite points. Through a given point , there passes infinite lines.
Line Segment is the part of the line that contains two points and all points between them. The two points are called end points.
Ray is a line segment when extended infinitely in one direction
Parallel lines Two lines in the same plane are said to be parallel, if they never meet.
Transversal is a line which cuts a pair of parallel is called a transversal.
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33min
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Basic Geometry Part 2 - Lecture 36
GEOMETRY
Geometry is the most important topic of maths section in PSTET. Geometry can be defined as the study of shapes.
Plane Geometry is related to the properties and relation of plane figures, such as angles, triangles, other polygons and circles.
Line is defined by its length but has no breadth. A line contains infinite points. Through a given point , there passes infinite lines.
Line Segment is the part of the line that contains two points and all points between them. The two points are called end points.
Ray is a line segment when extended infinitely in one direction
Parallel lines Two lines in the same plane are said to be parallel, if they never meet.
Transversal is a line which cuts a pair of parallel is called a transversal.
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35min
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Circle Basic Geometry Part 3 - Lecture 37
GEOMETRY
Geometry is the most important topic of maths section in PSTET. Geometry can be defined as the study of shapes.
Plane Geometry is related to the properties and relation of plane figures, such as angles, triangles, other polygons and circles.
Line is defined by its length but has no breadth. A line contains infinite points. Through a given point , there passes infinite lines.
Line Segment is the part of the line that contains two points and all points between them. The two points are called end points.
Ray is a line segment when extended infinitely in one direction
Parallel lines Two lines in the same plane are said to be parallel, if they never meet.
Transversal is a line which cuts a pair of parallel is called a transversal.
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37min
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Circle Basic Geometry Part 4 - Lecture 38
GEOMETRY
Geometry is the most important topic of maths section in PSTET. Geometry can be defined as the study of shapes.
Plane Geometry is related to the properties and relation of plane figures, such as angles, triangles, other polygons and circles.
Line is defined by its length but has no breadth. A line contains infinite points. Through a given point , there passes infinite lines.
Line Segment is the part of the line that contains two points and all points between them. The two points are called end points.
Ray is a line segment when extended infinitely in one direction
Parallel lines Two lines in the same plane are said to be parallel, if they never meet.
Transversal is a line which cuts a pair of parallel is called a transversal.
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26min
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Circle Basic Geometry Part 5 - Lecture 39
GEOMETRY
Geometry is the most important topic of maths section in PSTET. Geometry can be defined as the study of shapes.
Plane Geometry is related to the properties and relation of plane figures, such as angles, triangles, other polygons and circles.
Line is defined by its length but has no breadth. A line contains infinite points. Through a given point , there passes infinite lines.
Line Segment is the part of the line that contains two points and all points between them. The two points are called end points.
Ray is a line segment when extended infinitely in one direction
Parallel lines Two lines in the same plane are said to be parallel, if they never meet.
Transversal is a line which cuts a pair of parallel is called a transversal.
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19min
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Triangles Part 1 - Lecture 40
TRAINGLES
Summary
In this chapter you have studied the following points :
1. Two figures having the same shape but not necessarily the same size are called similar
figures.
2. All the congruent figures are similar but the converse is not true.
3. Two polygons of the same number of sides are similar, if (i) their corresponding angles
are equal and (ii) their corresponding sides are in the same ratio (i.e., proportion).
4. If a line is drawn parallel to one side of a triangle to intersect the other two sides in
distinct points, then the other two sides are divided in the same ratio.
5. If a line divides any two sides of a triangle in the same ratio, then the line is parallel to the
third side.
6. If in two triangles, corresponding angles are equal, then their corresponding sides are in
the same ratio and hence the two triangles are similar (AAA similarity criterion).
7. If in two triangles, two angles of one triangle are respectively equal to the two angles of
the other triangle, then the two triangles are similar (AA similarity criterion).
8. If in two triangles, corresponding sides are in the same ratio, then their corresponding
angles are equal and hence the triangles are similar (SSS similarity criterion).
9. If one angle of a triangle is equal to one angle of another triangle and the sides including
these angles are in the same ratio (proportional), then the triangles are similar
(SAS similarity criterion).
10. The ratio of the areas of two similar triangles is equal to the square of the ratio of their
corresponding sides.
11. If a perpendicular is drawn from the vertex of the right angle of a right triangle to the
hypotenuse, then the triangles on both sides of the perpendicular are similar to the
whole triangle and also to each other.
12. In a right triangle, the square of the hypotenuse is equal to the sum of the squares of the
other two sides (Pythagoras Theorem).
13. If in a triangle, square of one side is equal to the sum of the squares of the other two
sides, then the angle opposite the first side is a right angle.
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38min
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Triangles Part 2 - Lecture 41
TRAINGLES
Summary
In this chapter you have studied the following points :
1. Two figures having the same shape but not necessarily the same size are called similar
figures.
2. All the congruent figures are similar but the converse is not true.
3. Two polygons of the same number of sides are similar, if (i) their corresponding angles
are equal and (ii) their corresponding sides are in the same ratio (i.e., proportion).
4. If a line is drawn parallel to one side of a triangle to intersect the other two sides in
distinct points, then the other two sides are divided in the same ratio.
5. If a line divides any two sides of a triangle in the same ratio, then the line is parallel to the
third side.
6. If in two triangles, corresponding angles are equal, then their corresponding sides are in
the same ratio and hence the two triangles are similar (AAA similarity criterion).
7. If in two triangles, two angles of one triangle are respectively equal to the two angles of
the other triangle, then the two triangles are similar (AA similarity criterion).
8. If in two triangles, corresponding sides are in the same ratio, then their corresponding
angles are equal and hence the triangles are similar (SSS similarity criterion).
9. If one angle of a triangle is equal to one angle of another triangle and the sides including
these angles are in the same ratio (proportional), then the triangles are similar
(SAS similarity criterion).
10. The ratio of the areas of two similar triangles is equal to the square of the ratio of their
corresponding sides.
11. If a perpendicular is drawn from the vertex of the right angle of a right triangle to the
hypotenuse, then the triangles on both sides of the perpendicular are similar to the
whole triangle and also to each other.
12. In a right triangle, the square of the hypotenuse is equal to the sum of the squares of the
other two sides (Pythagoras Theorem).
13. If in a triangle, square of one side is equal to the sum of the squares of the other two
sides, then the angle opposite the first side is a right angle.
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26min
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Triangles Part 3 - Lecture 42
TRAINGLES
Summary
In this chapter you have studied the following points :
1. Two figures having the same shape but not necessarily the same size are called similar
figures.
2. All the congruent figures are similar but the converse is not true.
3. Two polygons of the same number of sides are similar, if (i) their corresponding angles
are equal and (ii) their corresponding sides are in the same ratio (i.e., proportion).
4. If a line is drawn parallel to one side of a triangle to intersect the other two sides in
distinct points, then the other two sides are divided in the same ratio.
5. If a line divides any two sides of a triangle in the same ratio, then the line is parallel to the
third side.
6. If in two triangles, corresponding angles are equal, then their corresponding sides are in
the same ratio and hence the two triangles are similar (AAA similarity criterion).
7. If in two triangles, two angles of one triangle are respectively equal to the two angles of
the other triangle, then the two triangles are similar (AA similarity criterion).
8. If in two triangles, corresponding sides are in the same ratio, then their corresponding
angles are equal and hence the triangles are similar (SSS similarity criterion).
9. If one angle of a triangle is equal to one angle of another triangle and the sides including
these angles are in the same ratio (proportional), then the triangles are similar
(SAS similarity criterion).
10. The ratio of the areas of two similar triangles is equal to the square of the ratio of their
corresponding sides.
11. If a perpendicular is drawn from the vertex of the right angle of a right triangle to the
hypotenuse, then the triangles on both sides of the perpendicular are similar to the
whole triangle and also to each other.
12. In a right triangle, the square of the hypotenuse is equal to the sum of the squares of the
other two sides (Pythagoras Theorem).
13. If in a triangle, square of one side is equal to the sum of the squares of the other two
sides, then the angle opposite the first side is a right angle.
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20min
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Arithmetic Progression - Lecture 43
Arithmetic Progression
An arithmetic progression is a sequence in which terms increase or decrease by a constant number called the common difference.
E.g., The sequence 2, 6, 10, 14, 18, 22, .… Is an arithmetic progression, whose first term is 2 and common difference is 4.
An arithmetic progression is represented by a, (a + d), (a + 2d), (a + 3d), ….., a + (n – 1) d.
Here a = first term
d = common difference
n = number of terms in the progression
The general term of an arithmetic progression is given by Tn = a + (n – 1) d
The sum of n terms of an arithmetic progression is given by S_n = n/2 [2a + (n – 1) d] 0r S_n = n/2[a+l] where l is the last term of arithmetic progression.
If a, b, c are in arithmetic progression, then b = (a+c)/2 where b is the arithmetic mean.
Fundas
If the same quantity is added or multiplied to each term of an AP, then the resulting series is also an AP.
If three terms are in AP, then they can be taken as (a – d), a, (a + d).
If four terms are in AP, then they can be taken as (a – 3d), (a – d), (a + d), (a +3d).
If five terms are in AP, then they can be taken as (a – 2d), (a – d), a, (a + d), (a + 2d).
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42min
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Mensuration - Lecture 44
Mensuration
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40min
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