Reasoning: 1/20 - 1/28 = 1/70
70 minutes
Ans: (C)
Question: A pipe can fill a cistern in 20 minutes whereas the cistern when fill can be emptied by a leak in 28 minutes. When both pipes are opened, find when the cistern will be full?
Options:
(A) 22 minutes
(B) 88 minutes
(C) 70 minutes
(D) 77 minutes
(E) 48 minutes
Rationale: 5C3 * 4C2 * 4C2 = 10*6*6 = 360.
The answer: (B)
Question: An analyst will recommend a combination of 3 industrial stocks, 2 transportation stocks, and 2 utility stocks. If the analyst can choose from 5 industrial stocks, 4 transportation stocks, and 4 utility stocks, how many different combinations of 7 stocks are possible?
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Options:
(A) 12
(B) 360
(C) 60
(D) 180
(E) 720
Reasoning: Final number = Initial number + 50%(original number) = 110 + 50%(110) = 110 + 55 = 165.
Ans: (E)
Question: 110 is increased by 50%. Find the final number.
Options:
(A) 100
(B) 110
(C) 150
(D) 155
(E) 165
Rationale: Must be either 5 heads or 5 tails
1/2*1/2*1/2*1/2*1/2 + 1/2*1/2*1/2*1/2*1/2
1/32 + 1/32 = 1/16
The answer: (D)
Question: When tossed, a certain coin has equal probability of landing on either side. If the coin is tossed 5 times, what is the probability that it will land on either side all 5 times?
Options:
(A) 1/5
(B) 1/10
(C) 1/12
(D) 1/16
(E) 1/32
Reasoning: C) 60- because the pattern is adding 12 each time.
Ans: (C)
Question: Scotty B is helping his brother Jimmy B with math patterns. Jimmy's paper has 12, 24, 36, 48, and a blank space.
What number should Jimmy B put in the blank space?
Options:
(A) 50
(B) 58
(C) 60
(D) 62
(E) 96
Reasoning: Largest 3 digit number is 999
After doing 999 88 we get remainder 31
Hence largest 3 digit number exactly divisible by 88 = 999 - 31 = 968
Ans: (E)
Question: Find the largest 3 digit number which is exactly divisible by 88?
Options:
(A) 765
(B) 907
(C) 944
(D) 954
(E) 968