The average age of 15 students of a class is 15 years. Out of these, the average age of 3 students is 14 years and that of the other 11 students is 16 years. The age of the 15th student is	Choose one:
A) 9 years
B) 11 years
C) 14 years
D) 7 years
E) 25 years

Rationale: "solution age of the 15 th student = [ 15 x 15 - ( 14 x 3 + 16 x 11 ) ] = ( 225 - 218 ) = 7 years . answer d"
Answer: D