Question

The average age of a family of 5 members is 20 years. If the age of the youngest member be 10 years then what was the average age of the family at the time of the birth of the youngest member? 1. 13.5 2. 14 3. 15 4. 12.5 a b c d

Answer 1

Answer:

4.12.5(d)

Step-by-step explanation:

by just using the average formula

• the sum of the age of the family including youngest boy also is 5*20=100
• by subtracting youngest member age from 100 gives 90
• now the average age family at the time of birth of youngest member is 90/4=12.5