The average of 1st 3 of 4 numbers is 6 and of the last 3 are 5. If the sum of the first and the last number is 17. What is the last numbers?	Select the correct option:
A) 4  B) 5  C) 6  D) 7  E) 8
A + B + C = 18   B + C + 7 = 15   A + 7 = 17   A – 7 = 3   A + 7 = 17   27 = 14   7 = 7   ANSWER:7
<result>D</result>
The average of 1st 3 of 4 numbers is 6 and of the last 3 are 5. If the sum of the first and the last number is 17. What is the last numbers?