The average of seven numbers is 4. The average of first three numbers is 2 and the average of last three numbers is 6. What is the middle number?
Options:
(A) 3
(B) 4
(C) 6
(D) 7
(E) 8 Now, let's think a bit. Some random thoughts:
The total of seven numbers = 7X4 = 28
The total of first 3 and last 3 numbers is = 3 X 2+3 X 6 = 24
So, the middle number is (28 - 24 ) = 4
The final answer: (B).