Q: The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
Options:
(A) 87
(B) 15
(C) 17
(D) 19
(E) 16
A: OK... Stream of consciousness: Average of 20 numbers = 0
Sum of 20 numbers = (0 * 20) = 0
It is quite possible that 19 of these numbers may be positive and if their sum is a, then 20th number is (-a).
The answer is (D).

Q: The price of a T.V. set worth Rs. 10000 is to be paid in 20 installments of Rs. 1000 each. If the rate of interest be 6% per annum, and the first installment be paid at the time of purchase, then the value of the last installment covering the interest as well will be?
Options:
(A) 9000
(B) 26699
(C) 96000
(D) 19000
(E) 26711
A: OK... Stream of consciousness: Money paid in cash = Rs. 1000
Balance payment = (10000 - 1000) = Rs. 9000
The answer is (A).

Q: he speed of a train is 90 kmph. What is the distance covered by it in 10 minutes?
Options:
(A) 25 kmph
(B) 15 kmph
(C) 17 kmph
(D) 95 kmph
(E) 14 kmph
A: OK... Stream of consciousness: 90 * 10/60 = 15 kmph
The answer is (B).

Q: The average age of A, B and C is 29 years. If the average age of A and C is 32 years, what is the age of B in years ?
Options:
(A) 19
(B) 35
(C) 20
(D) 32
(E) 23
A:

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
OK... Stream of consciousness: Age of B = Age of (A + B + C) â€“ Age of (A + C) = 29 Ã— 3 â€“ 32 Ã— 2 = 87 â€“ 64 = 23 years
The answer is (E).