question: What is the greatest positive integer x such that 4^x is a factor of 64^10?
Options:
(A) 5
(B) 9
(C) 10
(D) 20
(E) 30
answer: Stream of consciousness: 64^10 = (4^3)^10 = 4^30 The answer is (E).

q: A train 124 m long running at 68 kmph crosses a platform in 19 sec. What is the length of the platform?
Options:
(A) 338
(B) 234
(C) 240
(D) 881
(E) 271
a: Stream of consciousness: D = 68 * 5/18 = 19 = 358 124 = 234 The answer is (B).

question: An equity analyst needs to select 3 stocks for the upcoming year and rank these securities in terms of their investment potential. If the analyst has narrowed down the list of potential stocks to 7, in how many ways can she choose and rank her top 3 picks?
Options:
(A) 21
(B) 35
(C) 210
(D) 420
(E) 840
answer: Stream of consciousness: Number of ways of choosing 3 stocks = 7C3
Number of ways of ranking the chosen stocks = 3!
Hence total ways of choosing and ranking = 7C3 * 3! = 7!/4! = 7*6*5 = 210 The answer is (C).

q: How many seconds will a train 130 meters long take to cross a bridge 150 meters long if the speed of the train is 36 kmph?
Options:
(A) 28 sec
(B) 23 sec
(C) 24 sec
(D) 25 sec
(E) 26 sec
a: Stream of consciousness: D = 130 + 150 = 280
S = 36 * 5/18 = 10 mps
T = 280/10 = 28 sec The answer is (A).

question: Three pipes A, B and C can fill a tank from empty to full in 30 minutes, 20 minutes and 10 minutes respectively. When the tank is empty, all the three pipes are opened. A, B and C discharge chemical solutions P, Q and R respectively. What is the proportion of solution R in the liquid in the tank after 3 minutes?
Options:
(A) 6/15
(B) 6/11
(C) 6/14
(D) 6/12
(E) 6/13
answer: Stream of consciousness: Part filled by (A + B + C) in 3 minutes = 3(1/30 + 1/20 + 1/10) = 11/20
Part filled by C in 3 minutes = 3/10
Required ratio = 3/10 * 20/11 = 6/11 The answer is (B).

question: If 12 men can reap 120 acres of land in 36 days, how many acres of land can 54 men reap in 54 days?
Options:
(A) 186
(B) 188
(C) 810
(D) 167
(E) 861
answer:
Stream of consciousness: 12 men 120 acres 36 days
54 men ? 54 days
120 * 54/12 * 54/36
10 * 54 * 3/2
54 * 15 = 810 The answer is (C).