CAT 2017 Slot 2 — QA Question 6
Change in AverageEasy
The average height of 22 toddlers increases by 2 inches when two of them leave this group. If the average height of these two toddlers is one-third the average height of the original 22, then the average height, in inches, of the remaining 20 toddlers is
Answer & solution
Correct answer: 32
- A
30
- B
28
32
- D
26
Solution
Easy
Conserve total height. Let the original average be ; express the two leavers' total and the remaining toddlers' total, then equate to and solve.
1
Set up the totals. Original average , so total . The two who leave average , and the remaining average .
2
Solve for . Clear the fraction and collect terms.
3
Average of the remaining . It is .