The average age of applicants for a new job is 20, with a standard deviation of 8. The hiring manager is only willing to accept applicants whose age is within one standard deviation of the average age. Assuming that all applicants' ages are integers and that the endpoints of the range are included, what is the maximum number of different ages of the applicants?
Options:
(A) 8
(B) 16
(C) 17
(D) 18
(E) 34
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Minimum age = Average - 1 Standard deviation = 20 - 8 = 12
Maximum age = average + 1 Standard deviation = 20+ 8 = 28
Maximum number of different ages of the applicants = 28 - 12 + 1 = 17 So the answer is: (C).
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A, B and C can do a work in 8 days, 8 days and 12 days respectively. In how many days can all three of them working together, complete the work?
Options:
(A) 3
(B) 2 2/8
(C) 2 2/0
(D) 2 2/2
(E) 2 2/1
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Work done by all three of them in one day = 1/8 + 1/8 + 1/12 = 1/3
The number of days required = 3 days. So the answer is: (A).
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Two trains are moving at 40 kmph and 70 kmph in opposite directions. Their lengths are 150 m and 100 m respectively. The time they will take to pass each other completely is?
Options:
(A) 41/2 sec
(B) 5/2 sec
(C) 61/2 sec
(D) 71/6 sec
(E) 49/6 sec
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70 + 40 = 110 * 5/18 = 275/9mps
D = 150 + 100 = 250 m
T = 250 * 9/275 = 49/6 sec So the answer is: (E).
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