ЁЯУв Too many exams? DonтАЩt know which one suits you best? Book Your Free Expert ЁЯСЙ call Now!

    Question

    The ratio of the speed of boat in upstream to speed of

    boat in downstream is 7:9. If the boat can cover a total of 70 km upstream and 90 km downstream in 5 hours, then find the time taken by the boat to cover 200 km in still water.
    A 4.25 hours Correct Answer Incorrect Answer
    B 3.25 hours Correct Answer Incorrect Answer
    C 6.25 hours Correct Answer Incorrect Answer
    D 2.25 hours Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Let speed of boat in upstream and downstream be тАШ7xтАЩ km/h and тАШ9xтАЩ km/h respectively. 70/7x + 90/9x = 5 10/x + 10/x = 5 20 = 5x x = 4 Speed of boat in still water = (7x + 9x)/2 = 8x = 8 ├Ч 4 = 32 km/h Desired time = 200/32 = 6.25 hours

    Practice Next
    More Boats and streams Questions

    Relevant for Exams:

    ask-question