q: A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?
Options:
(A) 5 kmph
(B) 6 kmph
(C) 7 kmph
(D) 8 kmph
(E) 9 kmph
a: Speed downstream = d/t = 85/(2 1/2) = 34 kmph
Speed upstream = d/t = 45/(2 1/2) = 18 kmph
The speed of the stream = (34 - 18)/2 = 8 kmph The answer is (D).
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q: A train 200 meters long completely crosses a 300 meters long bridge in 45 seconds. What is the speed of the train is?
Options:
(A) 32
(B) 28
(C) 40
(D) 27
(E) 21
a: S = (200 + 300)/45 = 500/45 * 18/5 = 40 The answer is (C).
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q: 5,9,16,28,48,__
Options:
(A) 79
(B) 80
(C) 81
(D) 82
(E) 83
a: (9+5) +2 = 16
(16+9) +3 = 28
(28+16)+4 = 48
(48+28)+5 = 81 The answer is (C).
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q: Find the value of y from (12)^3 x 6^4 ÷ 432 = y?
Options:
(A) 2456
(B) 3456
(C) 4578
(D) 4290
(E) 5184
a:
Given Exp. = (12)3 x 64 = (12)3 x 64 = (12)2 x 62 = (72)2 = 5184
432 12 x 62 The answer is (E).
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