A 120 meter long train crosses a man standing on the platform in 6 sec. What is the speed of the train?
Options:
(A) 229
(B) 108
(C) 278
(D) 72
(E) 112
Answer and stream of consciousness: (D)
Stream of consciousness: S = 120/6 * 18/5 = 72 kmph

How many zeroes are there at the end of the number N, if N = 100! + 200! ?
Options:
(A) 73
(B) 49
(C) 20
(D) 48
(E) 24
Answer and stream of consciousness: (E)
Stream of consciousness: The number of zeroes at the end of 100! will be less than the number of zeroes at the end of 200!
Hence it would be sufficient to calculate the number of zeroes at the end of 100!
Number of zeroes = [100/5] + [100/25] + [100/125] = 20 + 4 + 0 = 24

In a race with 30 runners where 5 trophies will be given to the top 9 runners (the trophies are distinct: first place, second place, etc), how many ways can this be done?
Options:
(A) 9^5 ways
(B) 8^9 ways
(C) 7^8 ways
(D) 8^7 ways
(E) 8^6 ways
Answer and stream of consciousness: (A)
Stream of consciousness: 9 people can be prized with 5 distinct prizes in 9^5 ways

If a square and a rhombus stand on the same base, then the ratio of the areas of the square and the rhombus is?
Options:
(A) 1:1
(B) 1:2
(C) 1:9
(D) 1:6
(E) 1:4
Answer and stream of consciousness:
(A)
Stream of consciousness: A square and a rhombus on the same base are equal in are