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

    Question

    A boat can travel 16 km more in downstream than that in

    upstream, in 8 hours while the difference between the time taken by the same boat to travel 180 km and 120 km, in still water, is 4 hours. Find the approximate time taken by the boat to travel 200 km in downstream and 100 km in upstream.
    A 20 hours Correct Answer Incorrect Answer
    B 22 hours Correct Answer Incorrect Answer
    C 21 hours Correct Answer Incorrect Answer
    D 26 hours Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Let the speed of boat in still water and speed of stream be 'x' km/hr and 'y' km/hr, respectively. According to question; (180/x) - (120/x) = 4 Or, (60/x) = 4 So, x = 15 Now, 8 X (15 + y) = 8 X (15 - y) + 16 Or, 120 + 8y = 120 - 8y + 16 Or, 16y = 16 So, y = 1 So, downstream speed of the boat = (15 + 1) = 16 km/hr And, upstream speed of the boat = (15 - 1) = 14 km/hr Required time taken = (200/16) + (100/14) ~ (13 + 7) ~ 20 hours

    Practice Next

    Relevant for Exams: