Question

    In still water, the speed of boat ‘C’ is four times

    that of boat ‘D’. If both boats start towards each other from 280 km apart and meet in 4 hours, find the still water speed of boat ‘D’.
    A 18 km/h Correct Answer Incorrect Answer
    B 14 km/h Correct Answer Incorrect Answer
    C 24 km/h Correct Answer Incorrect Answer
    D 10 km/h Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    ATQ,

    Let still water speed of boat ‘D’ = y km/h

    Then, speed of boat ‘C’ = 4y km/h

    Let stream speed = x km/h

    Effective speed = y + 4y = 5y km/h

    So, 5y = 280 ÷ 4 = 70

    y = 70 ÷ 5 = 14

    Speed of boat ‘D’ in still water = 14 km/h

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