It is found that at least 2-3 questions are given to calculate AVERAGE based questions in SSC IBPS or other exam format. These questions are very easy to solve by using SIMPLE TRICKS in 2-3 Seconds after reading statement of question.
These FASTEST AVERAGE TRICKS helps in getting CUT-OFF score in exams. Use these tricks to solve NUMERICAL ABILIY section of SSC IBPS or other any other competitive exam.
FASTEST AVERAGE TRICKS are described as follows:
1. AVERAGE = Sum of numbers / Total numbers
2. If the AVERAGE of n number is m, then SUM of n numbers = mn
3. In case of Age calculation questions, if AVERAGE of age of n persons is x before (ago) m years, then the SUM of age of n persons = n(x + m) to get present age of the group.
4. AVERAGE = Sum of First & Last number / 2
5. AVERAGE = Sum of Middle Terms / 2
6. AVERAGE of Multiple of Any number = Sum of First & Last Number / 2
7. AVERAGE of first n natural numbers = (n+1) / 2
8. AVERAGE of first n consecutive n even numbers = (n + 1)
9. AVERAGE of first n consecutive n odd numbers = n
10. AVERAGE of square of first n natural numbers = [n(n+1)(2n+1)] / 6
11. AVERAGE of cubes of first n natural numbers = [n(n+1) / 2]2
12. SUM of 1-100 natural numbers = n (n-1) / 2
13. SUM of First n ODD numbers = n2
14. Geometric Mean (G. M.) of any numbers x, y, z = 3√x.y.z
15. Harmonic Mean (H. M.) of any numbers x, y, z = 1 / [1/3(1/x+1/y+1/z)]. Here 3 is the total number of which H. M. is to be calculated which can be changed if more than 3 numbers are used to calculate H. M. say if 4 numbers then it will become 4 & 5 for 5 and so-on.
16. If any person covers some distance in two parts with two different speeds. If he covers first part at a speed of S1 km/hr and second part at a distance of S2 km/hr, then AVERAGE speed during to cover the complete distance = 2 S1 S2 / (S1 + S2)
17. In case if the same person covers the whole journey in three different parts with different speeds S1 , S2 and S3 then AVERAGE speed = 3 S1 S2 S3 / (S1 S2 + S2 S3 + S3 S1)
18. If AVERAGE of any n persons/items is increased by x then the increased AVERAGE = nx
The average age of 10 persons in a committee is increased by 1 year. When two men age of 42 years and 38 years are replaced by two women. Find the average age of these women.
By using TRICK 18 (above),
The Total average age of n=10 persons increase age of m=1 year = 10x1 = 10 years.
Then Total age of two men go out from the group = 42 + 38 = 80 years
Total age of two women enters into group = 80 + 10 = 90
Then average age of these women = 90 / 2 = 45years each
The average age of husband and wife was 23 years when they got married 5 years ago. The age of husband, wife and children who was born during the interval is 20years now. How old is child now.
By using TRICK 3 (above)
5 years Ago average age of Husband + Wife = 23 years
Present Average age of Husband + Wife = 23+5 = 28 years
Sum of Present age of Husband + Wife = 28 x 2 = 56 year
Similarly Sum of Present age of Husband + Wife + Child = 20 x 3 = 60.
Thus the age of Child
= (Sum of Present age of Husband + Wife + Child) - Sum of Present age of Husband + Wife)
= 60-56 = 4 years
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