Maths Tips and Tricks 3
Average calculation
N = the number of terms .
S = the sum of the numbers in the set.
Average = S/N .
For example.
The marks of a student in five subjects are 96, 94, 92, 87, and 81, then what is the average score of the student?.
N = 5.
S = 96 + 94 + 92 + 87 + 81 = 450.
A = 450/5 = 90.
Another type questions .
1). There are 36 boys and 44 girls in a class. The average score of boys is 40 and girls are 35. Then what will be the average mark? .
Total mark of 36 boys = 36 x 40 = 1440.
Total mark of 44 girls = 35 x 44 = 1540.
Total mark of 80 Students = 1440 + 1540 = 2980 .
Average mark of the class = (2980 / 80).
Read full Tips & Tricks
S = the sum of the numbers in the set.
Average = S/N .
For example.
The marks of a student in five subjects are 96, 94, 92, 87, and 81, then what is the average score of the student?.
N = 5.
S = 96 + 94 + 92 + 87 + 81 = 450.
A = 450/5 = 90.
Another type questions .
1). There are 36 boys and 44 girls in a class. The average score of boys is 40 and girls are 35. Then what will be the average mark? .
Total mark of 36 boys = 36 x 40 = 1440.
Total mark of 44 girls = 35 x 44 = 1540.
Total mark of 80 Students = 1440 + 1540 = 2980 .
Average mark of the class = (2980 / 80).
Read full Tips & Tricks
Handshake Problem
Suppose there are n people in the party. The first person shakes hand with the other (n-1) guests. The second guest shakes hand with the other (n-2) guests. this will continue until the (n-1) th guest shakes hand with the nth guest.
Total number of handshakes is (n-1) + (n-2).. + 3 + 2 + 1. .
= ((n-1)(n))/2 .
For example, 6 people in a party shake hand with other guests. So how many handshakes will be there?.
=((6-1)(6))/2.
=15.
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Total number of handshakes is (n-1) + (n-2).. + 3 + 2 + 1. .
= ((n-1)(n))/2 .
For example, 6 people in a party shake hand with other guests. So how many handshakes will be there?.
=((6-1)(6))/2.
=15.
Read full Tips & Tricks
Simple and Compound Interest Formula
P - Principal, the sum of money lent or borrowed. .
R - Rate of interest: Annual interest, often expressed as a percentage. .
T - Time period for which the money is lent or borrowed. .
Simple Interest = Principal * Time * Rate of interest / 100 .
SI = 4000× 8% × 4 = 4000× 0.08 × 4.
= 1280. .
In compound interest , the principal amount with interest after the first time period becomes the part of principal for the next time period.
CI = [P (1 + R/100)^T] – P .
Total amount = [P (1 + R/100)^T] .
If time period is half-yearly, .
Amount = P[1 + (R/2)/100]^2T .
If time period is quarterly, .
Amount = P[1 + (R/4)/100 Read full Tips & Tricks
R - Rate of interest: Annual interest, often expressed as a percentage. .
T - Time period for which the money is lent or borrowed. .
Simple Interest = Principal * Time * Rate of interest / 100 .
SI = 4000× 8% × 4 = 4000× 0.08 × 4.
= 1280. .
In compound interest , the principal amount with interest after the first time period becomes the part of principal for the next time period.
CI = [P (1 + R/100)^T] – P .
Total amount = [P (1 + R/100)^T] .
If time period is half-yearly, .
Amount = P[1 + (R/2)/100]^2T .
If time period is quarterly, .
Amount = P[1 + (R/4)/100 Read full Tips & Tricks
Combinations and Permutations
Permutation and combination related questions are common in PSC and Bank exams.
Before going to Combinations and Permutations, first lean about factorial. .
If n is a positive integer then, factorial of n is denoted as n! . .
4! = (1 x 2 x 3 x 4 ) = 24.
Permutations are for lists of items, whose order matters and combinations are for group of items where order doesn’t matter. in other words, .
When the order of items doesn\\\'t matter, it is called as Combination.
When the order of items does matter it is called as Permutation.
The number of permutations of n objects taken r at a time is determined by using this formula:.
C(n,r)=n!/((n−r)!r!) .
Combination : Picking a team of 3 people from a football coaching group of 10. C(10,3) = 10!(3!(10−3)!) = 120. . Read full Tips & Tricks
Before going to Combinations and Permutations, first lean about factorial. .
If n is a positive integer then, factorial of n is denoted as n! . .
4! = (1 x 2 x 3 x 4 ) = 24.
Permutations are for lists of items, whose order matters and combinations are for group of items where order doesn’t matter. in other words, .
When the order of items doesn\\\'t matter, it is called as Combination.
When the order of items does matter it is called as Permutation.
The number of permutations of n objects taken r at a time is determined by using this formula:.
C(n,r)=n!/((n−r)!r!) .
Combination : Picking a team of 3 people from a football coaching group of 10. C(10,3) = 10!(3!(10−3)!) = 120. . Read full Tips & Tricks
