The average of seven numbers is 21. The average of first three numbers is 19 and the average of last three numbers is 23. What is the middle number?\nOptions:\n(A) 20\n(B) 22\n(C) 18\n(D) 19\n(E) 21 Let's think first. Stream of consciousness:
User
The total of seven numbers = 7X21 = 147\nThe total of first 3 and last 3 numbers is = 3 X 19+3 X 23 = 126\nSo, the middle number is (147 - 126 ) = 21
So, the answer is (E).
Assistant