The average of 1st 3 of 4 numbers is 7 and of the last 3 are 5. If the sum of the first and the last number is 13. What is the last numbers?	Pick one
A) 4 B) 5 C) 3.5 D) 7 E) 8
A + B + 3.5 = 21   B + 3.5 + D = 15   A + D = 13   A – D = 6   A + D = 13   2D = 7   D = 3.5   ANSWER:3.5
<result>C</result>
The average of 1st 3 of 4 numbers is 7 and of the last 3 are 5. If the sum of the first and the last number is 13. What is the last numbers?