New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    A train covers a certain distance at a speed of 60 km/h

    and the next same distance with a speed of 75 km/h and the next same distance with a speed of 100 km/h. find the average speed?
    A 60 km/hr Correct Answer Incorrect Answer
    B 63 km/hr Correct Answer Incorrect Answer
    C 31.5 km/hr Correct Answer Incorrect Answer
    D 75 km/hr Correct Answer Incorrect Answer

    Solution

    Since the distance is same in all the conditions. Therefore, Average speed = 3xyz/(xy + yz + zx) Average speed = 3 x 60 x 75 x 100/(60 x 75 + 75 x 100 + 100 x 60) Average speed = 3 x 60 x 75 x 100/(4500 + 7500 + 6000) = 1350000/18000 = 75 km/hr

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