question: A train running at the speed of 60 km/hr crosses a pole in 12 sec. What is the length of the train?
Options:
(A) 120 m
(B) 180 m
(C) 200 m
(D) Cannot be determined
(E) None of these
answer: Stream of consciousness: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 12 = 200 m The answer is (C).

q: A goods train runs at the speed of 72 km/hr and crosses a 250 m long platform in 26 sec. What is the length of the goods train?
Options:
(A) 49 sec
(B) 50 sec
(C) 48 sec
(D) 43 sec
(E) 32 sec
a: Stream of consciousness: D = 540 + 180 = 720
S = 54 * 5/18 = 15 mps
T = 720/15 = 48 se The answer is (C).

question: If a certain coin is flipped, the probability that the coin will land heads is 1/2. If the coin is flipped 5 times, what is the probability that it will land heads up on the first 3 flips and not on the last 2 flips?
Options:
(A) 3/5
(B) 1/2
(C) 1/5
(D) 1/8
(E) 1/32
answer: Stream of consciousness: On the first three flips, you must get heads. Whats the probability of getting heads ? Its 1/2
So for the first three flips, your probability is (1/2)^3 = 1/8
Now for the last two, you want to get tails only. Whats the prob of getting tails ? Well, its the same as prob of getting a heads, namely, 1/2
For the last two flips, your probability is (1/2)^2 = 1/4
So your overall probability for the event in question is 1/8*1/4 = 1/32 The answer is (E).

q: A train 420 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 36 sec
(B) 16 sec
(C) 17 sec
(D) 88 sec
(E) 12 sec
a: Stream of consciousness: Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 420 * 2/35 = 36 sec The answer is (A).

question: An seller earns an income of Re 3 on the first day of his business. On every subsequent day, he earns an income which is just thrice of that made on the previous day. On the 15th day of business, he earns an income of:
Options:
(A) 19
(B) 22
(C) 25
(D) 20
(E) 36
answer: Stream of consciousness: 2nd day he earns = 3(2 3)
3rd day he earns = 3(3 3)
On 15th day he earns 3(15 -3) = 36 rupees The answer is (E).

question: The speed of a boat in still water is 60kmph and the speed of the current is 10kmph. Find the speed downstream and upstream?
Options:
(A) 40, 68 kmph
(B) 70, 50 kmph
(C) 90, 60 kmph
(D) 40, 60 kmph
(E) 20, 60 kmph
answer:
Stream of consciousness: Speed downstream = 60 + 10 = 70 kmph
Speed upstream = 60 - 10 = 50 kmph The answer is (B).