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

    Question

    Speed of a car is (v + 3) km/h, which is 10 km/h less

    than that of bike. Time taken by car to cover 84 km is 25% less than the time taken by bike to cover 168 km. Length of a train is (5v + 11) metres. If speed of train is (v - 5) m/s, then find the time taken (in seconds) by train to cross a man standing on a platform of length 420 metres.
    A 6 Correct Answer Incorrect Answer
    B 9 Correct Answer Incorrect Answer
    C 12 Correct Answer Incorrect Answer
    D 10 Correct Answer Incorrect Answer
    E 8 Correct Answer Incorrect Answer

    Solution

    Speed of bike = v + 3 + 10 = (v + 13) km/h 84 ÷ (v + 3) = (3/4) × 168 ÷ (v + 13) Or, 84(v + 13) = 126(v + 3) Or, 84v + 1092 = 126v + 378 Or, 42v = 714 Or, v = 17 Length of train = 5 × 17 + 11 = 96 metres Speed of train = 17 − 5 = 12 m/s Since we need to calculate the time taken by train to cross the man standing on the platform, so the length of the platform will not be considered. Required time = 96 ÷ 12 = 8 seconds

    Practice Next
    More Trains Questions
    ask-question