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    Question

    A race track is in the shape of a rectangle with length

    of 75 metres and area of 3000 m2. A car takes 20 seconds to make one lap around the perimeter of this track. If the car and a person whose speed is 5 m/s, started moving at the same time along the perimeter of the track but in opposite directions, then find the distance between the car and the person, 3 seconds before they cross each other.
    A 40.5 metres Correct Answer Incorrect Answer
    B 41.5 metres Correct Answer Incorrect Answer
    C 39.5 metres Correct Answer Incorrect Answer
    D 49.5 metres Correct Answer Incorrect Answer

    Solution

    Area of the track = length of track x breadth of track = 75 x breadth of track = 3000 So, breadth of track = 3000 ÷ 75 = 40 So, perimeter of the track = (75 + 40) x 2 = 230 metres So, speed of the car = (230/20) = 11.5 m/s Relative speed of the car with respect to the person = 11.5 + 5 = 16.5 m/s So, distance between the car and the person, 3 seconds before they cross each other = 16.5 x 3 = 49.5 metres

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