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

    Question

    A boat can travel 30 km downstream in 2 hours and return

    upstream in 3 hours. What is the speed of the boat in still water?
    A 10 km/h Correct Answer Incorrect Answer
    B 15 km/h Correct Answer Incorrect Answer
    C 12.5 km/h. Correct Answer Incorrect Answer
    D 25 km/h Correct Answer Incorrect Answer

    Solution

    Downstream speed = Distance/Time = 30/2 = 15 km/h. Upstream speed = Distance/Time = 30/3 = 10 km/h. Let speed of the boat in still water be x and speed of the current be y. Then, x + y = 15, x - y = 10. Adding both equations: 2x = 25 → x = 12.5 km/h. Answer: c) 12.5 km/h.

    Practice Next