New 55% Off on All Courses - Enroll Now! Click Here

    Question

    A man can row 13 km/hr in still water. When the river is

    running at 5 km/hr, it takes him 6.5 hours to row to a place and back. How far is the place?
    A 36 km Correct Answer Incorrect Answer
    B 35 km Correct Answer Incorrect Answer
    C 26 km Correct Answer Incorrect Answer
    D 34 km Correct Answer Incorrect Answer
    E none of these Correct Answer Incorrect Answer

    Solution

    Let distance = x [if gte msEquation 12]>x [if !msEquation]-->[endif]-->km, Rate upstream = 13 - 5 = 8 km/hr Rate downstream= 13 + 5 = 18 km/hr. [if gte msEquation 12]>∴ [if !msEquation]-->[endif]-->`:.` Time taken upstream =`x/8` [if gte msEquation 12]> x 8 [if !msEquation]-->[endif]--> Time taken downstream =`x/18` [if gte msEquation 12]> x 18 [if !msEquation]-->[endif]--> => x/8 + x/18 = 6.5 ⇒ 13x/72 = 6.5 ⇒ x = 36 km .

    Practice Next

    Relevant for Exams: