Question

ten years ago the average age of a family of four members was 25 years. two children having been born the average age of the family is the same today. what is the age of the youngest child if they differ in age by 2 years? (a) 3 years (b) 2 years (c) 4 years (d) 8 years

Answer 1

Total age of 4 members, 10 years ago = (24 x 4) years = 96 years.

Total age of 4 members now = [96 + (10 x 4)] years = 136 years.

Total age of 6 members now = (24 x 6) years = 144 years.

Sum of the ages of 2 children = (144 - 136) years = 8 years.

Let the age of the younger child be x years.

Then, age of the elder child = (x+2) years.

So, x+(x+2) =8 <=> x=3

Age of younger child  =  3 years.

ans is (A)3