The average of 15 result is 60. Average of the first 10 of them is 10 and that of the last 10 is 80. Find the 8th result?
Options:
(A) 35
(B) 200
(C) 150
(D) 250
(E) 300 Think first, then make a decision. Some random thoughts:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Sum of all the 13 results = 15 * 60 = 900
Sum of the first 7 of them = 10 * 10 = 100
Sum of the last 7 of them = 10 * 80 = 800
So, the 8th number = 900 + 100 - 800 = 200. So the answer is (B).