Question

    150 unit of work can be completed by P alone in 25 days.

    P started working alone and joined by Q after 15 days such that they completed the remaining work in 6 days. Find the number of days taken by Q to complete the whole work alone.
    A 37.5 days Correct Answer Incorrect Answer
    B 46 days Correct Answer Incorrect Answer
    C 13.5 days Correct Answer Incorrect Answer
    D 14 days Correct Answer Incorrect Answer
    E 12 days Correct Answer Incorrect Answer

    Solution

    Let the efficiency of Q = x units/day Efficiency of P = (150/25) = 6 units/day According to question: 6 × 15 + (6 + x) × 6 = 150 Or, 90 + 36 + 6x = 150 Or, 6x = 150 – 126 Or, 6x = 24 Or, x = 4 Number of days taken by Q to complete the work alone = (150/4) = 37.5 days

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