Boats And Streams
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A boat covers 12 km upstream and 18 km downstream in 3 hours, while it covers 36 km upstream and 24 km downstream in 
What is the speed of the current?
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1.5 km/hr
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1 km/hr
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2 km/hr
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2.5 km/hr
C.
2 km/hr
If the speed of boat in still water be x kmph and that of current by y kmph, then
...(i)
By equation (i) x 3 - equation (ii)
From equation (i),
∴ Speed of current 
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A boat moves downstream at the rate of 1 km in 
minutes and upstream at the rate of 5 km an hour. what is the speed of the boat in the still water?
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-
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4 km/hour
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8 km/hour
B.
Rate downstream of boat
Rate downstream of boat = 5 kmph
Speed of boat in still water = 
A man can row 15 km per hour downstream and 9 km per hour upstream. The speed (in kmph) of the boat in still water is
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10
-
12
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15
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8
B.
12
Speed of boat in still water
A man can row against the current three-fourth of a kilometre in 15 minutes and returns the same distance in 10 minutes. The ratio of his speed to that of the current is
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3 : 5
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5 : 3
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1 : 5
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5 : 1
D.
5 : 1
Speed of boat in still water = x kmph
Speed of current = y kmph
From equations (i) and (ii),
From equation (ii)
If the speed of a boat in still water is 20 km/hr and the speed of the current is 5 km/hr, then the time taken by the boat to travel 100 km with the current is
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2 hours
-
3 hours
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4 hours
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7 hours
C.
4 hours
Distance = 100 km
Speed of boat in still water = 20 km/hr
Speed of current = 5 km/hr
Relative speed = (20 + 5)km/hr = 25 km/hr
Required Time
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Mock Test Series
Mock Test Series