Question

    Raju travels 150 km in 7.5 hours moving downstream. The

    speed of the stream is 5 km/h. Find the speed at which Raju should row the boat to reach back at the same time.
    A 18 km/h Correct Answer Incorrect Answer
    B 7.5 km/h Correct Answer Incorrect Answer
    C 10 km/h Correct Answer Incorrect Answer
    D 25 km/h Correct Answer Incorrect Answer

    Solution

    Let the Speed of boat in still water =B km/h Speed of stream =S km/h Downstream speed of the boat = 150/7.5 =20 km/h Here, B + S = 20 B + 5 = 20   B = 15 speed of the boat in still water = 15 km/h Now, Raju needs to cover the same distance in 7.5 hours upstream. Upstream speed should be 20 km/h. B-S =20 B-5 =25 B =25km/h.

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