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) 40
(B) 48
(C) 45
(D) 50
(E) 25
a: D = 540 + 180 = 720
S = 54 * 5/18 = 15 mps
T = 720/15 = 48 sec The answer is (B).
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q: The edge of a cube is 7a cm. Find its surface?
Options:
(A) 24a8
(B) 24a4
(C) 24a1
(D) 24a2
(E) 294a2
a: 6a2 = 6 * 7a * 7a = 294a2 The answer is (E).
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q: A can do a piece of work in 12 days. When he had worked for 2 days B joins him. If the complete work was finished in 8 days. In how many days B alone can finish the work?
Options:
(A) 28 days
(B) 76 days
(C) 16 days
(D) 18 days
(E) 19 days
a: 8/12 + 6/x = 1
X = 18 days The answer is (A).
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q: Two persons A and B can complete a piece of work in 30 days and 45 days respectively. If they work together, what part of the work will be completed in 3 days?
Options:
(A) 1/8
(B) 1/3
(C) 1/6
(D) 1/2
(E) 5/3
a:
A's one day's work = 1/30
B's one day's work = 1/45
(A + B)'s one day's work = 1/30 + 1/45 = 1/18
The part of the work completed in 3 days = 3 (1/18) = 1/6. The answer is (C).
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