question_answer

Average age of A, B and C is 10 years. If the average age of A and C is 9 years, then how many years old is B?

A) 9                                 

B) 10             

C) 11                               

D) 12

Correct Answer: D

Solution :

Average of A, Band C = 10 years A + B + C = 30 yr. Now, (A + C) + B = 30 yr. 18 + B = 30 B = 30 ? 18 = 12 yrs.