question: How many terminating zeroes R does 200! have?
Options:
(A) 40
(B) 48
(C) 49
(D) 55
(E) 64
answer: Stream of consciousness: You have 40 multiples of 5, 8 of 25 and 1 of 125. This will give 49 zeros. The answer is (C).

q: A boat moves upstream at the rate of 1 km in 20 minutes and down stream 1 km in 12 minutes. Then the speed of the current is :
Options:
(A) 1 kmph
(B) 2 kmph
(C) 3 kmph
(D) 2.5 kmph
(E) 3.5 kmph
a: Stream of consciousness: Rate upstream = (1/20 *60) = 3 kmph
Rate dowm stream = 1/12 * 60 = 5 kmph
Rate of the current = (5-3) = 1 kmph The answer is (A).

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) 287
(B) 699
(C) 677
(D) 168
(E) 200
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 (E).

q: How long does a train 100 m long traveling at 54 kmph takes to cross a station of 250 m in length?
Options:
(A) 22 sec
(B) 20 sec
(C) 15 sec
(D) 23 sec
(E) 16 sec
a: Stream of consciousness: D = 100 + 245 = 345 m
S = 54* 5/18 = 15
T = 345 * 1/15 = 23 sec The answer is (D).

question: A man rows his boat 78 km downstream and 56 km upstream, taking 4 hours each time. Find the speed of the stream?
Options:
(A) 6
(B) 5
(C) 7
(D) 8
(E) 3
answer: Stream of consciousness: Speed downstream = d/t = 78/(4) = 20 kmph
Speed upstream = d/t = 56/(4) = 14 kmph
The speed of the stream = (20 - 14)/2 = 3 kmph The answer is (E).

question: A train 140 m long, running with a speed of 63 km/hr will pass a tree in?
Options:
(A) 18 sec
(B) 6 sec
(C) 8 sec
(D) 15 sec
(E) 7 sec
answer:
Stream of consciousness: Speed = 63 * 5/18 = 35/2 m/sec
Time taken = 140 * 2/35 = 8 se The answer is (C).