CAT 2017 Slot 2QA 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

  • A

    30

  • B

    28

  • 32

  • D

    26

Solution

Let the average height of 22 toddlers be ‘x’ inches.

Now as the average height of the 2 toddlers who leave the group is one-third the average height of the entire group 22, their average = x/3 inches.

Further, the average height of the balance 20 toddlers in terms of x will be ‘x + 2’ inches. So the average height of all 22 toddlers can be expressed as

x = 2(x3)+20(x+2)22

Hence, 22x = 2x/3 + 20x + 40

⇒ x = 30

So the average height of the balance

20 toddlers will be 30 + 2 or 32 inches.

Hence, option (c).

CAT 2017 Slot 2 QA Q6: The average height of 22 toddlers increases by 2 inches when two of them leave this group. If the average heig — Solution | TheCATExam