New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    A, B, and C together can do a piece of work in 28 days,

    whereas C alone can do the same work in 42 days. How long will A and B take together to finish it?
    A 28 Correct Answer Incorrect Answer
    B 14 Correct Answer Incorrect Answer
    C 84 Correct Answer Incorrect Answer
    D 56 Correct Answer Incorrect Answer

    Solution

    (A+B+C)C 2842 84 32 The efficiency of A+B+C =3 Efficiency of C =2 Efficiency of (A+B) =A+B+C -C=3-2=1 A and B work both together =84/1 = 84 days.

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