Question

    A man rows a boat 54 kms in 6 hours downstream and

    returns upstream in 10 hours. The speed of the stream (in km per hour) is:
    A 1.8 km/hr Correct Answer Incorrect Answer
    B 5 km/hr Correct Answer Incorrect Answer
    C 4.5 km/hr Correct Answer Incorrect Answer
    D 7.2 km/hr Correct Answer Incorrect Answer
    E 8 km/hr Correct Answer Incorrect Answer

    Solution

    Rate downstream = 54/6 = 9 km/hr Rate upstream = 54/10 = 5.4 km/hr Now, speed of the stream = (rate downstream – rate upstream)/2 ⇒ (9 – 5.4)/2 = 1.8 km/hr

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