Question

Choose the correct answer from the alternatives given :
The average age of 4 boys, five years ago was 9 years. On including a new boy, the present average age of all the five is 15 years. The present age of the new boy is

• A. $14$ years
• B. $18$ years
• C. $15$ years
• D. $19$ years

Answer 1

The correct option is D $19$ years

Present average age of 4 boys $(9+5)$ = $14$ years.
Sum of Present ages of the 4 boys = 14 $\times$ 4 = $56$ years
Present sum of ages of the 5 boys = 15 $\times$ 5= $75$ years
Present age of the new boy = $(75-56)$= $19$ years