10 व्यकतीयो वाले परिवार की औसत आयु 20 वर्ष है। यदि परिवार के सबसे छोटे सदस्य की आयु 10 वर्ष है, तब परिवार की औसत आयु सबसे छोटे सदस्य के जन्म के समय ज्ञात करे ?

Options

A. `27.14 years`
B. `12.5 years`
C. `14.27 years`
D. `11(1)/(2) years`

Answer

D

Explanation

According to the question
Average age of a family of 10 members is =20 years
Sum of the age of 10 members =20 x 10 =200 years
If the age of youngest member is =10 years
Sum of the age of 9 members at the time of birth of youngest member =200-10 x 10 =200-10
=100 years
`therefore` Average of 9 members is =`100/9=11 1/9` years