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    Question

    The time taken by a boat to

    travel 'd' kilometers downstream is 8 hours, while the time taken to travel (d - 60) kilometers upstream is 10 hours. The speed of the current is equal to one-fifth of the boat's speed in downstream conditions. Determine the speed of the boat in still water.
    A 42 km/h Correct Answer Incorrect Answer
    B 36 km/h Correct Answer Incorrect Answer
    C 24 km/h Correct Answer Incorrect Answer
    D 22 km/h Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    ATQ, Let the speed of the boat in still water be 'U' km/hr and the speed of the current be 'V' km/hr (U + V)/5 = V (U + V)/V = 5/1 U + V = 5p V = p U = 5p – p = 4p km/hr U – V = 4p – p = 3p km/hr 5p × 8 – 3p × 10 = 60 40p – 30p = 60 10p = 60 p = 6 km/hr Speed of the boat in still water = 4 × 6 = 24 km/hr

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