Question

    Boat ‘A’ can cover 320 km in still water in 16

    hours. In still water, if the ratio of the speed of boat ‘A’ to that of ‘B’ is 5:3 and the speed of stream is 5 km/hr then find the time taken by boat ‘B’ to cover the 306 km in downstream.
    A 10 hours Correct Answer Incorrect Answer
    B 12 hours Correct Answer Incorrect Answer
    C 18 hours Correct Answer Incorrect Answer
    D 15 hours Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Speed of boat ‘A’ in still water = 320/16 = 20 km/hr Speed of boat ‘B’ in still water = 20 × (3/5) = 12 km/hr Downstream speed of boat ‘B’ = 12 + 5 = 17 km/hr Time taken by boat ‘B’ to cover 306 km in downstream = 306/17 = 18 hours

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