The average of twelve numbers is 7. The average of first nine numbers is 6 and the average of last two numbers is 10. What is the middle number?\nOptions:\n(A) A) 9\n(B) B) 10\n(C) C) 12\n(D) D) 7\n(E) E) 13 Stream of consciousness first, then make a decision:
User
The total of twelve numbers = 12X7 = 84\nThe total of first 9 and last 2 numbers is = 9 X 6+2 X 10 = 74\nSo, the middle number is (84 - 74 ) = 10
Thus, the answer is (B).
Assistant