Question
Person βRβ can complete a task in 60 days, and
together with βSβ, they can do it in 24 days. If βSβ worked alone for 18 days and then left, how many days will βRβ take to finish the remaining work?Solution
Let the total work = 120 units {L.C.M of 60 and 24}
Then, efficiency of βRβ = 120 Γ· 60 = 2 units/day
Combined efficiency of βRβ and βSβ = 120 Γ· 24 = 5 units/day
So, efficiency of βSβ = 5 β 2 = 3 units/day
So, work done by βSβ alone in 18 days = 3 Γ 18 = 54 units
Remaining work = 120 β 54 = 66 units
Time taken by 'R' alone to complete the remaining work = 66 Γ· 2 = 33 days
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