Question

    A can do a work in 8 days and B in 12 days. If they work

    on it together for 2 days then in how many days the remaining work will be completed by B?
    A 9 days Correct Answer Incorrect Answer
    B 5 days Correct Answer Incorrect Answer
    C 7 days Correct Answer Incorrect Answer
    D 4 days Correct Answer Incorrect Answer

    Solution

    Total work = Number of days×1 day’s work (efficiency) Total work = LCM (8, 12) = 24 unit 1 day’s work of A = 24/8 = 3 unit 1 day’s work of B = 24/12 = 2 unit 1 day’s work of (A + B) = 3 + 2 = 5 unit Now, 2 day’s work of (A + B) together = 2× 5 = 10 unit Remaining work = 24 – 10 = 14 Remaining work completed by B = 14/2 = 7 days

    Practice Next