If from a group of 5 people, an old member is replaced by a new one, the average age is same as it was 3 years ago. What is the difference between the ages of the old member and the new one?
Choose the correct option.
A) 12 B) 15 C) 11 D) 18 E) 16
Explanation:   The present average age is (x + 3) when the old member is present and it equals to x when an old member is replaced by a new one.   The difference in the ages of the old member and the new one is equal to the difference in the total age before and after the replacement = 15 years.   ANSWER: 15
<result>B</result>
If from a group of 5 people, an old member is replaced by a new one, the average age is same as it was 3 years ago. What is the difference between the ages of the old member and the new one?