The average age of a group of 10 persons was decreased by 3 years when one person, whose age was 40 years, was replaced by a new person. Find the age of the new person?
Choose the correct choice.
A) 18
B) 56
C) 12
D) 17
E) 10

Rationale: "initial average age of the 10 persons be p . age of the new person q . sum of the ages of the initial 10 persons = 10 p new average = ( p - 3 ) 10 ( p - 3 ) = 10 p - 40 + q = > q = 10 answer : e"
Answer: E