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

    Question

    A ship covers 96 km upstream and 144 km downstream in 8

    hours and 6 hours, respectively. Find the time taken by the same ship to cover 180 km in still water.
    A 10 hrs Correct Answer Incorrect Answer
    B 12 hrs Correct Answer Incorrect Answer
    C 18 hrs Correct Answer Incorrect Answer
    D 24 hrs Correct Answer Incorrect Answer

    Solution

    ATQ, Let speed of the ship in still water be ‘x’ km/h and speed of the stream be ‘y’ km/h Upstream speed of ship = (x – y) = (96/8) = 12 km/h --------- (I) Downstream speed of ship = (x + y) = (144/6) = 24 km/h ---------- (II) On adding equation (I) and equation (II), we have: 2x = 36 Or, x = 18 So, speed of the ship in still water = 18 km/h Therefore, time taken by the ship to cover 180 km in still water = (180/18) = 10 hours

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