John found that the average of 15 numbers is 40. If 11 is added to each number then the mean of number is?  Select the correct option
A) 51  B) 45  C) 65  D) 78  E) 64

Rationale: "( x + x 1 + . . . x 14 ) / 15 = 40 51 option a"
Answer: A