The average student age of a certain class which has 45 students is 14. If one student aged 15 go to another class and the age of the class teacher is included the average changes to 14.66. What is the age of class teacher?	Choose the correct choice from the following choices:  A) 30  B) 35  C) 38  D) 40  E) 45

Rationale: sum of ages of class before replacement = 45 x 14 = 630 sum of ages of class without teacher = 630 - 15 = 615 sum of ages of class after replacement = 45 x 14.66 = 660 age of teacher = 660 - 615 = 45 answer : e
Answer: E