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    Question

    Ratio of speed of a boat in still water to speed of stream

    is 14:2 respectively.Ratio of the time taken by the boat to cover a distance of (x + 42) km upstream and (x – 66) km in downstream is 7:5 respectively. Find the value of x.
    A 556 Correct Answer Incorrect Answer
    B 606 Correct Answer Incorrect Answer
    C 520 Correct Answer Incorrect Answer
    D 440 Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    ATQ,

    Let speed of boat in still water and speed of stream is ‘14a’ km/h and ‘2a’ km/h respectively.

    Upstream speed = 14a – 2a = 12a km/h

    Downstream speed = 14a + 2a = 16a km/h

    So, [(x + 42)/12a]/[(x – 66)/16a] = 7/5

    Or, 5(x + 42) = 6(x – 66)

    Or, 5x + 210 = 6x – 396

    Or, x = 606

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