Question
A and B can complete a work in 40 and 60 days
respectively. They started a work which is to be completed in 20 days. But it was found that they are lagging behind the schedule, so a third person C was appointed after 12 days to complete the work on time. In how many days C can alone complete the work?Solution
A and B worked for 20 days. In 1 days, they could have completed work (1/40 + 1/60) = 1/24 So, in 20 days, they did (1/24) *20 = 5/6 This means C did 1 – 5/6 = 1/6 of work in 8 days So, he can do work alone in 48 days.
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