IBPS Clerk Prelims Model Paper 8

If the boy had not been born, the average age of the family would be 35 years.
So, total age of 4 members of the family = 35 × 4 = 140
But now, it is 140 + 5 and there are 5 members in the family now.
So, average age =

145

5

= 29 years