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 17. What is the last numbers? Pick one:
A) 2  B) 4  C) 6  D) 5  E) 7
A + B + C = 48   B + C + D = 45   A + D = 17   A – D = 3   A + D = 17   2D = 14   D = 7   ANS7R 7
<result>E</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 17. What is the last numbers?