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

    Question

    Two cars start from a place with a speed of 55 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 11 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

    Solution

    Distance covered in 15 minutes at 55 km/hr =55 x (15/60) Distance covered in 11 minutes at (55 + x) km/hr = (11/60) x (55 + x) Now, Distance covered in 15 minutes at 55 km/hr = Distance covered in 11 minutes at (55 + x) km/hr ⇒ 55 x (15/60) = (11/60) x (55 + x) ⇒ 825 x 12 = 605 + 11x ⇒ 825 = 605 + 11x ⇒ 11x = 825 - 605 = 220 ⇒ x = 20 km/hr

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