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

    Question

    Two cars start from a place with a speed of 70 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 14 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 70 km/hr = 70 x (15/60) Distance covered in 14 minutes at (70 + x) km/hr = (14/60) x (70 + x) Now, Distance covered in 15 minutes at 70 km/hr = Distance covered in 14 minutes at (70 + x) km/hr ⇒ 70 x (15/60) = (14/60) x (70 + x) ⇒ 70 x 15 = 980 + 14x ⇒ 1050 = 980 + 14x ⇒ 14x = 1050 - 980 = 70 ⇒ x = 5 km/hr

    Practice Next

    Relevant for Exams: