Question

There are 14 people in a joint family and the average age of all the family members is 30 years. Now, a baby boy is born in that family. After 4 years, what will be the average age of all the family members?
1. 35 years
2. 33 years
3. 32 years
4. 30 years

Answer 1

Correct Answer - Option 3 : 32 years

Let, the sum of age of 14 people = x years

Average of 14 people = x/14

According to question;

x/14 = 30 years

x = 420 years

After 4 years;

Baby age = 4 years

So, the sum of age of 15 people after 4 years = 420 + (15 × 4)

= 420 + 60 = 480 years

Now, 

The average of 15 people including baby = 480/15

= 32 years

Hence, The average age of family members after 4 years is "32 years".