Number of people (in lakhs) in five cities A–E and ratio of three age groups I:II:III. (I: 0–<21; II: 21–<41; III: 41+.)

For city C, if the people turning 21 next year number 16000, the newborns number 32000, and age group III stays the same, what will be the new ratio of people in the different age groups?

A31 : 31 : 60 ✓ Correct

B31 : 32 : 60

C31 : 32 : 56

D21 : 23 : 35

Correct answer: (A) 31 : 31 : 60

Explanation

The new ratio is 31 : 31 : 60, so that is the answer.

City C group I is 4.8 lakh; adding 32000 newborns and removing 16000 gives 496000.

Group II is 4.8 lakh; adding the 16000 who turned 21 gives 496000.

Group III stays at 9.6 lakh, which is 960000.

So the counts are 496000, 496000 and 960000.

This simplifies to 31 : 31 : 60.

Want more like this? Create a free account to practise a full test, track your progress, and get spaced-repetition review.