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

    Question

    A cheetah can catch a deer running with a speed of 108

    km/h and is 66 meters ahead of it, in 12 seconds. Find the time taken by the cheetah to catch a zebra that is 115 metres ahead of it and is running with a speed which is 80% of that of the deer.
    A 10 seconds Correct Answer Incorrect Answer
    B 11 seconds Correct Answer Incorrect Answer
    C 12 seconds Correct Answer Incorrect Answer
    D 13 seconds Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Speed of the deer = 108 km/h = 108 × (5/18) = 30 m/s Distance covered by the cheetah in 12 seconds = 66 metres + distance covered by the deer in 12 seconds = 66 + 30 × 12 = 66 + 360 = 426 metres So, speed of the cheetah = 426/12 = 35.5 m/s Speed of the zebra = 30 × (80/100) = 24 m/s So, relative speed of the cheetah with respect to the zebra = 35.5 – 24 = 11.5 m/s Hence, time taken by the cheetah to catch the zebra = 115/11.5 = 10 seconds

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