If 4 men can reap 40 acres of land in 15 days, how many acres of land can 16 men reap in 30 days?
Options:
(A) 320
(B) 240
(C) 369
(D) 489
(E) 125
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4 men 40 acres 15 days
16 men ? 30 days
40 * 16/4 * 30/15
40 * 4 * 2
40 * 8 = 320 So the answer is: (A).
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Twelve coins are tossed simultaneously. In how many of the outcomes will the third coin turn up a head?
Options:
(A) 2^9
(B) 2^11
(C) 3 * 2^8
(D) 3 * 2^9
(E) 3 * 2^10
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Fix the third coin as H. The remaining 11 coins have 2^11 outcomes. So the answer is: (B).
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On average, the bottle-nosed dolphin comes up for air once every three minutes; the beluga whale, a close relative, comes up for air on average once every six minutes. The number of times a bottle-nosed dolphin would come up for air in a 24 hour period is approximately what percent greater than the number of times a beluga whale would come up for air in that same period?
Options:
(A) 25%
(B) 50%
(C) 75%
(D) 100%
(E) 150%
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Dolphin once in 3 min;
Beluga once in 6 min;
So, dolphin comes up 2 times frequently than beluga, which is 150% (6-3)/2*100. So the answer is: (E).
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