Question
168 unit of work can be completed by P alone in 28 days.
P started working alone and joined by Q after 10 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 = (168/28) = 6 units/day According to question: 6 × 10 + (6 + x) × 6 = 168 Or, 60 + 36 + 6x = 168 Or, 6x = 168 – 96 Or, 6x = 72 Or, x = 12 Number of days taken by Q to complete the work alone = (168/12) = 14 days
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