q: The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
Options:
(A) 17
(B) 16
(C) 17
(D) 19
(E) 62
a: OK... 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: Every year an amount increases by 1/8th of itself. How much will it be after two years if its present value is Rs.64000?
Options:
(A) Rs.81000
(B) Rs.80000
(C) Rs.75000
(D) Rs.64000
(E) Rs.68000
a: OK... 64000* 9/8 * 9/8 = 81000
The answer is (A).

q: A 180 meter long train crosses a man standing on the platform in 6 sec. What is the speed of the train?
Options:
(A) 228
(B) 108
(C) 1266
(D) 188
(E) 211
a:
OK... S = 180/6 * 18/5 = 108 kmph
The answer is (B).