Quantitative Aptitude

Averages

1,527 Questions
All Basic average and reverse calculation 405 Adding or removing an observation 342 Weighted and combined averages 320 Replacement and correction of a recorded value 233 Ratio shortcut for two-group mixtures 111 Equal-distance average speed 59 Age, score, weight, and spending applications 32 Consecutive terms and arithmetic progressions 25

Averages Questions

Multiple choice

The average age of 8 members of a committee is the same as it was 5 years ago, because an old member has been replaced by a young member. Find the age difference between the old member and the young member?

  1. 32 years

  2. 36 years

  3. 40 years

  4. 48 years
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let the sum of ages be S. After 5 years, the sum would be S + 8*5 = S + 40. Replacing an old member (O) with a young member (Y) makes the sum S + 40 - O + Y. Since the average is the same, the sum is the same: S = S + 40 - O + Y. Thus, O - Y = 40.

Multiple choice

Find the average of 28, 29, 33, 35 & 35

  1. 30

  2. 32

  3. 33

  4. 34
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The average is the sum of the numbers divided by the count. Sum = 28 + 29 + 33 + 35 + 35 = 160. Count = 5. Average = 160 / 5 = 32.