8. A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 mph, the speed of the stream is:
A.2 mph
B.2.5 mph
C.3 mph
D.4 mph

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9. A man can row at 5 kmph in still water. If the velocity of current is 1 kmph and it takes him 1 hour to row to a place and come back, how far is the place?
A.2.4 km
B.2.5 km
C.3 km
D.3.6 km

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10.  A boat covers a certain distance downstream in 1 hour, while it comes back in 1-1/2 hours. If the speed of the stream be 3 kmph, what is the speed of the boat in still water?
A.12 kmph
B.13 kmph
C.14 kmph
D.15 kmph

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11. A boat takes a total time of three hours to travel downstream from P and Q and upstream back from Q to P. What is the speed of the boat in still water? I. The speed of the river current is 1 km per hour. II. The distance between P and Q is 4 km.
A. alone sufficient while II alone not sufficient to answer
B.II alone sufficient while I alone not sufficient to answer
C.Either I or II alone sufficient to answer
D.Both I and II are necessary to answer

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12. What is the speed of the boat in still water? I.It takes 2 hours to cover the distance between A and B downstream. II. It takes 4 hours to cover the distance between A and B upstream.
A.I alone sufficient while II alone not sufficient to answer
B.II alone sufficient while I alone not sufficient to answer
C.Either I or II alone sufficient to answer
D.Both I and II are not sufficient to answer

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13. What is the speed of the boat in still water? I. The boat covers a distance of 48 kms in 6 hours while running upstream. II. The boat covers the same distance in 4 hours while running downstream.
A.I alone sufficient while II alone not sufficient to answer
B.II alone sufficient while I alone not sufficient to answer
C.Either I or II alone sufficient to answer
D.Both I and II are necessary to answer

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14. What is the speed of the boat in still water? I. The speed downstream is 12 kmph. II. The speed upstream is 4 kmph. III. In a to and fro journey between two points, the average speed of the boat was 6 kmph.
A.I and II only
B.All I, II and III
C.III, and either I or II
D.Any two of the three

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