Question

    Two cars start from a place with a speed of 60 km/hr at

    an interval of 15 minutes. What is the speed of a man coming from the opposite direction towards the place if he meets the cars at an interval of 12 minutes?
    A 20 km/hr Correct Answer Incorrect Answer
    B 15 km/hr Correct Answer Incorrect Answer
    C 10 km/hr Correct Answer Incorrect Answer
    D 5 km/hr Correct Answer Incorrect Answer
    E 25 km/hr Correct Answer Incorrect Answer

    Solution

    Distance covered in 15 minutes at 60 km/hr =60 x (15/60) Distance covered in 12 minutes at (60 + x) km/hr = (12/60) x (60 + x) Now, Distance covered in 15 minutes at 60 km/hr = Distance covered in 12 minutes at (60 + x) km/hr ⇒ 60 x (15/60) = (12/60) x (60 + x) ⇒ 60 x 15 = 720 + 12x ⇒ 900 = 720 + 12x ⇒ 12x = 900 - 720 = 180 ⇒ x = 15 km/hr

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