The average age of 15 students of a class is 15 years. Out of these, the average age of 5 students is 14 years and that of the other 9 students is 16 years. The age of the 15th student is?	Choose the correct choice from the following choices:
A) 9
B) 11
C) 15
D) 12
E) 20

Rationale: "age of the 15 th student = 15 * 15 - ( 14 * 5 + 16 * 9 ) = 225 - 214 = 11 years answer is b"
Answer: B