New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    A boat travels faster than the stream by 28 km/h. It

    covers a distance of 112 km upstream and returns 132 km downstream, all within 7 hours. Calculate the speed of the boat in still water, expressing your answer in meters per second.
    A 36 m/s Correct Answer Incorrect Answer
    B 20 m/s Correct Answer Incorrect Answer
    C 18 m/s Correct Answer Incorrect Answer
    D 10 m/s Correct Answer Incorrect Answer
    E 30 m/s Correct Answer Incorrect Answer

    Solution

    Let speed of stream = ‘x’ km/h Speed of boat = (x + 28) km/h Upstream speed = x + 28 – x = 28 km/h Downstream speed = x + x + 28 = ‘2x + 28’ km/h According to question; 112/28 + 132/(2x + 28) = 7 Or, 132/(2x + 28) = 3 Or, 2x + 28 = 44 Or, x = 8 Seed of boat = 8 + 28 = 36 km/h = 36 × 5/18 = 10 m/s Hence, option d.

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