Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?
Options:
(A) 60 gallons
(B) 100 gallons
(C) 120 gallons
(D) 180 gallons
(E) 130 gallons
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Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40
Volume of 1/40 part = 3 gallonsVolume of whole = 3 * 40 = 120 gallons. So the answer is: (C).
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In a school of 300 boys, 44% of Muslims, 28% Hindus, 10% Sikhs and the remaining of other communities. How many belonged to the other communities?
Options:
(A) 54
(B) 63
(C) 70
(D) 42
(E) 31
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44 + 28 + 10 = 82%
100 82 = 18%
300 * 18/100 = 54 So the answer is: (A).
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If X and Y are both positive two-digit integers and share no digits, and X > Y, what is the smallest possible value of X - Y?
Options:
(A) 0
(B) 1
(C) 2
(D) 3
(E) 9
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Answer = B = 1
20 - 19 = 30-29 = 40-39 = 50-49 = 1 So the answer is: (B).
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