New RBI Grade B 2025 Notification will come Soon! Enroll Here

    Question

    A man rows a boat 72 kms in 5 hours downstream and

    returns upstream in 12 hours. The speed of the stream (in km per hour) is:
    A 7.2 km/hr Correct Answer Incorrect Answer
    B 2.1 km/hr Correct Answer Incorrect Answer
    C 4.2 km/hr Correct Answer Incorrect Answer
    D 3 km/hr Correct Answer Incorrect Answer
    E 10.2 km/hr Correct Answer Incorrect Answer

    Solution

    Rate downstream = 72/5 = 14.4 km/hr Rate upstream = 72/12 = 6 km/hr Now, speed of the stream = (rate downstream – rate upstream)/2 ⇒ (14.4 – 6)/2 = 4.2 km/hr

    Practice Next