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    Question

    Distance between a point of A and point B in a river is

    32 km and the flow of the stream is from A to B. If the speed of the boat is 10 km/h and speed of the stream is 6 km/h. The boat goes from B to A and then comes back. Find the total distance covered by the boat after 17 hours of travel since the time of starting?
    A 84 km Correct Answer Incorrect Answer
    B 78 km Correct Answer Incorrect Answer
    C 62 km Correct Answer Incorrect Answer
    D 92 km Correct Answer Incorrect Answer
    E none of these Correct Answer Incorrect Answer

    Solution

    The resulting speed in upstream is 10 – 6 = 4 km/h.
    And the resulting speed in downstream is 10 + 6 = 16 km/h.
    Since the boat is moving upstream from B to A.
    So time taken is 32/4 = 8 hours
    Now in downstream it takes 32/16= 2 hours
    Now, it will travel 7 hours in up stream, so the distance travelled = 4 x 7 = 28 km
    Total distance travelled = 32 + 32 + 28 = 92 km

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