New RBI Grade B Notification Out - 94 Vacancies - Prepare with Us!

    Register

    Question

    A man can swim at a speed of 5.5 km/hr in still water. He swims upstream from a certain point in the river and then back to the same point. If the speed of the current of the river is 2.5 km/hr. Find the average speed of his total journey

    A 4.4km/h Correct Answer Incorrect Answer
    B 3.5km/h Correct Answer Incorrect Answer
    C 5.5km/h Correct Answer Incorrect Answer
    D 4.5km/h Correct Answer Incorrect Answer

    Solution

    Given; speed of man in still water = 5.5 km/h  Speed of stream = 2.5 km/h  Speed in upstream = 5.5 – 2.5 = 3 km/h Speed in downstream = 5.5 + 2.5 = 8 km/h Average speed= =(2s1 s2)/(s1+s2 ) =(2×3×8)/(3+8)=48/11 =4.36km/h

    Practice Next