The average of seven numbers is 24. The average of first three numbers is 14 and the average of last three numbers is 19. What is the middle number?\nOptions:\n(A) 27\n(B) 29\n(C) 31\n(D) 34\n(E) 69
A step-by-step solution is:
(E)
The total of seven numbers = 7X24 = 168\nThe total of first 3 and last 3 numbers is = 3 X 14+3 X 19 = 99\nSo, the middle number is (168 - 99 ) = 69.

Thus, the answer is (E)