Question
180 unit of work can be completed by P alone in 30 days.
P started working alone and joined by Q after 18 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.Solution
Let the efficiency of Q = x units/day Efficiency of P = (180/30) = 6 units/day According to question: 6 × 18 + (6 + x) × 6 = 180 Or, 108 + 36 + 6x = 180 Or, 6x = 180 – 144 Or, 6x = 36 Or, x = 6 Number of days taken by Q to complete the work alone = (180/6) = 30 days
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