Question

    A can do a work in 9 days and B in 12 days. If they work

    on it together for 3 days then in how many days the remaining work will be completed by B?
    A 6 days Correct Answer Incorrect Answer
    B 5 days Correct Answer Incorrect Answer
    C 10 days Correct Answer Incorrect Answer
    D 4 days Correct Answer Incorrect Answer
    E 8 days Correct Answer Incorrect Answer

    Solution

    Total work = Number of days×1 day’s work (efficiency) Total work = LCM (9, 12) = 36 unit 1 day’s work of A = 36/9 = 4 unit 1 day’s work of B = 36/12 = 3 unit 1 day’s work of (A + B) = 4 + 3 = 7 unit Now, 3 day’s work of (A + B) together = 3× 7 = 21 unit Remaining work = 36 – 21 = 15 Remaining work completed by B = 15/3 = 5 days

    Practice Next