q: How long does a train 100 m long traveling at 72 kmph takes to cross a tunnel of 1400 m in length?
Options:
(A) 70 sec
(B) 60sec
(C) 82 sec
(D) 75 sec
(E) 62 sec
a: D = 1400+100 = 1500 m
S = 72 * 5/18 = 20
T = 1500 * 1/20 = 75 sec The answer is (D).
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q: For some integer y, y^2 - 5 is divisible by all of the following EXCEPT
Options:
(A) 29
(B) 30
(C) 31
(D) 38
(E) 41
a: Hint: y^2-5 (y is an integer) is never multiple of 3 (try to prove this), hence 30 is out. The answer is (B).
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q: A train running at the speed of 60 km/hr crosses a pole in 3 sec. What is the length of the train?
Options:
(A) 56
(B) 78
(C) 27
(D) 79
(E) 50
a: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 3 = 50 m The answer is (E).
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q: If Rs.7500 are borrowed at C.I at the rate of 4% per annum, then after 5 years the amount to be paid is?
Options:
(A) 3377
(B) 2688
(C) 2688
(D) 9125
(E) 1268
a:
A = 7500(26/25)^5 = 9125 The answer is (D).
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