Question
‘A’ and ‘B’ can do a piece of work in 30 days
and 40 days, respectively. They started working together but ‘A’ left after 9 days. Find the time taken by ‘B’ to complete the remaining work.Solution
Let total amount of work be 120 units (LCM of 30 and 40). Efficiency of ‘A’ = 120/30 = 4 units/day Efficiency of ‘B’ = 120/40 = 3 units/day Amount of work done by ‘A’ and ‘B’ together in 9 days = (4 + 3) × 9 = 63 units Time taken by B to complete remaining work = {(120 – 63)/3} = 19 days
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