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


    Question

    A person travels from town A to town B at 40 km/h and

    returns from B to A at 60 km/h. Find his average speed for the whole journey.
    A 32 km/h Correct Answer Incorrect Answer
    B 48 km/h Correct Answer Incorrect Answer
    C 62 km/h Correct Answer Incorrect Answer
    D 23 km/h Correct Answer Incorrect Answer

    Solution

    Let distance A to B = D km. Time from A to B = D/40 Time from B to A = D/60 Total distance = 2D Total time = D/40 + D/60 = D(1/40 + 1/60) LCM(40, 60) = 120 1/40 + 1/60 = 3/120 + 2/120 = 5/120 = 1/24 Total time = D × 1/24 = D/24 Average speed = Total distance / Total time = 2D / (D/24) = 2D × (24/D) = 48 km/h

    Practice Next

    Relevant for Exams:

    ask-question