Question
A motorboat in still water travels at a speed of 16
km/hr. It goes 27 km upstream in 2 hour 15 minutes. The time taken by it to cover the same distance down the stream will be :Solution
Speed of the motorboat upstream = 27/(9/4) = 12 km/hr Let the speed of the current be x km/hr ⇒ 16 – x = 12 ⇒ x = 4 km/hr Speed of motor boat downstream = 16 + 4 = 20 km/hr Time taken to cover 27 km at 20 km/hr = 27/20 = 27/20 hours or 1 hour 21 minutes
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