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

    Question

    A cheetah can catch a deer running with a speed of 90

    km/h and is 75 meters ahead of it, in 15 seconds. Find the time taken by the cheetah to catch a zebra that is 160 metres ahead of it and is running with a speed which is 80% of that of the deer.
    A 15 seconds Correct Answer Incorrect Answer
    B 14 seconds Correct Answer Incorrect Answer
    C 17 seconds Correct Answer Incorrect Answer
    D 16 seconds Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Speed of the deer = 90 km/h = 90 × (5/18) = 25 m/s Distance covered by the cheetah in 15 seconds = 75 metres + distance covered by the deer in 15 seconds = 75 + 25 × 15 = 75 + 375 = 450 metres So, speed of the cheetah = 450/15 = 30 m/s Speed of the zebra = 25 × (80/100) = 20 m/s So, relative speed of the cheetah with respect to the zebra = 30 – 20 = 10 m/s Hence, time taken by the cheetah to catch the zebra = 160/10 = 16 seconds

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