What percent is 70 of 280?
Options:
(A) 12 %
(B) 25 %
(C) 26 %
(D) 27 %
(E) 28 %
Answer and stream of consciousness: (B)
Stream of consciousness: 70/280 = 1/4
1/4 × 100 = 25 %


If f(x) = x^4/(x^4 - 1), what is f(1/x) in terms of f(x)?
Options:
(A) f(x) 
(B) 1/-f(x) 
(C) -2/-f(x) 
(D) -3/-f(x) 
(E) -f(x) 
Answer and stream of consciousness: (E)
Stream of consciousness: If x = 2 then f(x) = 16/15 and f(1/x) = -16/15 which is equal to -f(x)


Find the average of the first 25 natural numbers?
Options:
(A) 8
(B) 9
(C) 13
(D) 11
(E) 12
Answer and stream of consciousness: (C)
Stream of consciousness: Average of the first 'n' natural numbers = (n + 1)/2
We get (25 + 1)/2 = 13


The average of seven numbers is 18. The average of first three numbers is 12 and the average of last three numbers is 19. What is the middle number?
Options:
(A) 25
(B) 27
(C) 29
(D) 33
(E) 34
Answer and stream of consciousness:

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
(D)
Stream of consciousness: The total of seven numbers = 7X18 = 126
The total of first 3 and last 3 numbers is = 3 X 12+3 X 19 = 99
So, the middle number is (126 - 93 ) = 33