Question

    A race track is in the shape of a rectangle with length of 25 metres and area of 4500 m2. A car takes 10 seconds to make one lap around the perimeter of this track. If the car and a person whose speed is 4 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 135 metres Correct Answer Incorrect Answer
    B 125 metres Correct Answer Incorrect Answer
    C 115 metres Correct Answer Incorrect Answer
    D 145 metres Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Area of the track = length of track x breadth of track = 25 x breadth of track = 4500 So, breadth of track = 4500 ÷ 25 = 180 So, perimeter of the track = (25 + 180) x 2 = 410 metres So, speed of the car = (410/10) = 41 m/s Relative speed of the car with respect to the person = 41 + 4 = 45 m/s So, distance between the car and the person, 3 seconds before they cross each other = 45 x 3 = 135 metres

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