Question

    A and B together can complete a piece of work in

    30 days while A alone can complete 50% of the work in 40 days. Find the time taken by B to complete 75% of the work.
    A 30 days Correct Answer Incorrect Answer
    B 36 days Correct Answer Incorrect Answer
    C 32 days Correct Answer Incorrect Answer
    D 35 days Correct Answer Incorrect Answer
    E 30 days Correct Answer Incorrect Answer

    Solution

    Time taken by A to complete the whole work = 40/0.50 = 80 days
    Let total work = 240 units
    Amount of work done by A and B together in one day = 240/30 = 8 units
    Amount of work done by A alone in one day = 240/80 = 3 units
    Amount of work done by B in one day = 8 – 3 = 5 units
    Desired time = 0.75 × 240/5 = 36 days

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