📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!


    âš¡ Month End Offer - Flat 52% Off On All Courses! Enroll Now âš¡
    00:00:00 AM Left

    Question

    A train of length (L + 50) meters crosses a man running in

    the same direction in 25 seconds. The same train crosses a bridge of length (L - 100) meters in 30 seconds. If the speed of the man is 18 kmph, then find the value of 'L'.
    A 350 Correct Answer Incorrect Answer
    B 250 Correct Answer Incorrect Answer
    C 325 Correct Answer Incorrect Answer
    D 375 Correct Answer Incorrect Answer
    E 350 Correct Answer Incorrect Answer

    Solution

    Let the speed of the train be 'S' m/s,

    Speed of the man = 18 kmph = 5 m/s

    Length of the train = (L + 50) metres

    ATQ,

    L + 50 = (S - 5) X 25

    L = 25S - 175 --- (i)

    Sum of the length of Train and bridge = L + 50 + L – 100 = (2L - 50) metres

    Now,

    2L - 50 = 30S

    Using value of 'L' from equation (i), we get:

    2 X (25S - 175) - 50 = 30S

    Or, 50S - 350 - 50 = 30S

    Or, 20S = 400

    So, 'S' = 20

    Required value of 'L' = 25 X 20 - 175 = 325

    Practice Next
    ask-question