Question

    Speeds of train 'A' and train 'B' are in the ratio 4:5,

    respectively. Train 'B' can completely overtake train 'A' in 180 seconds. If lengths of train 'A' and train 'B' are 360 metres and 540 metres, respectively, then find the time taken by the two trains to cross each other while they are running in opposite directions.
    A 30 seconds Correct Answer Incorrect Answer
    B 25 seconds Correct Answer Incorrect Answer
    C 20 seconds Correct Answer Incorrect Answer
    D 15 seconds Correct Answer Incorrect Answer

    Solution

    Let the speeds of train 'A' and train 'B' be '4x' m/s and '5x' m/s, respectively.

    ATQ;

    (360 + 540) / (5x - 4x) = 180
    ⇒ 900 / x = 180 ⇒ x = 5

    So, required time = (360 + 540) / (4×5 + 5×5) = 900 / 45 = 20 seconds

    Practice Next
    ask-question