Question

    P can complete a work in 12 days working 8 hours a day,

    Q can complete the same work in 8 days working 10 hours a day. If both P and Q work together, working 8 hours a day, in how many days can they complete the work?
    A 5(5/11) Correct Answer Incorrect Answer
    B 5(6/11) Correct Answer Incorrect Answer
    C 6(5/11) Correct Answer Incorrect Answer
    D 6(6/11) Correct Answer Incorrect Answer

    Solution

    ATQ,

    P's rate: P completes the work in 96 hours (12 days × 8 hours/day). So, P’s work rate is 1/96 of the work per hour. Q's rate: Q completes the work in 80 hours (8 days × 10 hours/day). So, Q’s work rate is 1/80 of the work per hour. When they work together, their combined work rate is:

    Thus, together they complete 11/480 of the work per hour. The time taken to complete the work is:

    Since they work 8 hours a day, the number of days they will take is:

     

    or  5(5/11) 

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