Question

    A cheetah can catch a deer running with a speed of 72

    km/h and is 72 meters ahead of it, in 8 seconds. Find the time taken by the cheetah to catch a zebra that is 195 metres ahead of it and is running with a speed which is 70% of that of the deer.
    A 13 seconds Correct Answer Incorrect Answer
    B 10 seconds Correct Answer Incorrect Answer
    C 12 seconds Correct Answer Incorrect Answer
    D 15 seconds Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Speed of the deer = 72 km/h = 72 × (5/18) = 20 m/s Distance covered by the cheetah in 8 seconds = 72 metres + distance covered by the deer in 8 seconds = 72 + 20 × 8 = 72 + 160 = 232 metres So, speed of the cheetah = 232/8 = 29 m/s Speed of the zebra = 20 × (70/100) = 14 m/s So, relative speed of the cheetah with respect to the zebra = 29 – 14 = 15 m/s Hence, time taken by the cheetah to catch the zebra = 195/15 = 13 seconds

    Practice Next