q: 4 buses runs between Chennai and Mysore. If a man goes from Chennai to Mysore by a bus and comes back to Mysore by another bus, then the total possible ways are
Options:
(A) 4
(B) 8
(C) 12
(D) 16
(E) None of these
a: Since the man can go in 4 ways and can back in 3 ways. Therefore total number of ways are 4 x3 = 12ways. The answer is (C).
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q: The speed of a boat in still water is 90kmph and the speed of the current is 20kmph. Find the speed downstream and upstream?
Options:
(A) 40, 68 kmph
(B) 110, 70 kmph
(C) 90, 60 kmph
(D) 40, 60 kmph
(E) 20, 60 kmph
a: Speed downstream = 90 + 20 = 110 kmph
Speed upstream = 90 - 20 = 70 kmph The answer is (B).
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q: If six persons sit in a row, then the probability that three particular persons are always together is?
Options:
(A) 1/5
(B) 1/4
(C) 1/9
(D) 1/6
(E) 1/1
a: Six persons can be arranged in a row in 6! ways. Treat the three persons to sit together as one unit then there four persons and they can be arranged in 4! ways. Again three persons can be arranged among them selves in 3! ways. Favourable outcomes = 3!4! Required probability = 3!4!/6! = 1/5 The answer is (C).
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q: It is the New Year and Mandy has made a resolution to lose weight this year. She plans to exercise and do yoga. For exercise she plans to workout at the gym and ride her bicycle in the ratio of 2:3 everyday. She will also do yoga in the ratio, yoga:exercise = 2:3. If she rides her bike for 18 minutes, how much time will she spend doing yoga? (rounded to minutes)
Options:
(A) 30 min.
(B) 41 min.
(C) 17 min.
(D) 23 min.
(E) 25 min.
a:
The ratio is 2:3 = gym:ride, so (18)(3/2) = 27 minutes at the gym, and 27 + 18 = 45 minutes exercise, so (2/3)(45) = 30 minutes yog The answer is (A).
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