Question
A and B together can complete a work in 20 days. After
working together for 8 days, B leaves, and A completes the remaining work in 16 more days. In how many days can B alone complete the entire work?Solution
Let the total work be W units. Work done by A and B together in 8 days = 8 × (W/20) = 2W/5 units Remaining work = W - 2W/5 = 3W/5 units A completes 3W/5 units in 16 days, so A’s 1-day work = (3W/5) / 16 = 3W/80 units A and B together complete W/20 units per day, so B’s 1-day work = (W/20 - 3W/80) = W/80 units Therefore, B can complete the entire work in 80 days.
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