Question

    The speed of a boat in still water is 5 times the speed

    of the stream. If the difference between the upstream and downstream speed of the boats is 24 km/hr, then find the time taken by the boat to travel 384 km in upstream.
    A 5 hours Correct Answer Incorrect Answer
    B 2 hours Correct Answer Incorrect Answer
    C 8 hours Correct Answer Incorrect Answer
    D 6 hours Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Let the speed of the stream be ‘x’ km/hr Therefore, speed of the boat in still water = 5x km/hr Upstream speed of the boat = 5x – x = 4x km/hr Downstream speed of the boat = x + 5x = 6x km/hr According to the question, 6x – 4x = 24 => 2x = 24 => x = 12 Therefore, upstream speed of the boat = 4x = 48 km/hr Required time taken = 384/48 = 8 hours

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