q: A wheel rotates 20 times every minute and moves 30 cm during each rotation. How many metres does the wheel move in one hour?
Options:
(A) 360 metre
(B) 12 metre
(C) 320 metre
(D) 1200 metre
(E) 260 metre
a: Stream of consciousness: Number of times wheel moves in 1 hour = 20 * 30 = 1200
:. Distance moves = (1200*30) cms = 36000 cms
In metres = 360 metre The answer is (A).
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q: If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 2 strokes ?
Options:
(A) 3/4
(B) 7/8
(C) 1/4
(D) 1/8
(E) 1/16
a: Stream of consciousness: Left After 1st stroke = 1/2
Left After 2nd stroke = 1/2 * 1/2 = 1/4
So removed = 1- 1/4 = 3/4 The answer is (A).
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q: A train 540 meters long is running with a speed of 54 kmph. The time taken by it to cross a tunnel 180 meters long is?
Options:
(A) 66 sec
(B) 46 sec
(C) 48 sec
(D) 65 sec
(E) 64 sec
a:
Stream of consciousness: D = 540 + 180 = 720
S = 54 * 5/18 = 15 mps
T = 720/15 = 48 se The answer is (C).
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