Sum of age of 9 children born at interval of 9 years is 369. What is the age of youngest child?

M4maths Previous Puzzles

26 Jun 2020 Age

Sum of age of 9 children born at interval of 9 years is 369. What is the age of youngest child?

OPtion

1) 12
2) 8
3) 5
4) 16
5) 11
6) 15
7) 30
8) 18
9) 4
10) None of these

Solution

Let the ages of children be x, (x+9*1),
(x+9*2).... (x+7*8) years.

=> x + (x+9*1) + (x+9*2)+ (x+9*3) + (x+9*4) + (x+9*5) + (x+9*6)+ (x+9*7) + (x+9*8) = 369
=> 9x + 324 = 369
=> x = 5

Correct Option: 3 Best Solution (3)