The average of 1st 3 of 4 numbers is 16 and of the last 3 are 15. If the sum of the first and the last number is 13. What is the last numbers?  Select
A) 2 B) 4 C) 6 D) 5 E) 7
A + B + C = 48   B + C + 5 = 45   A + 5 = 13   A – 5 = 3   A + 5 = 13   25 = 10   5 = 5
<result>D</result>
The average of 1st 3 of 4 numbers is 16 and of the last 3 are 15. If the sum of the first and the last number is 13. What is the last numbers?