Question
‘D’ alone can finish a job in 50 days, while ‘D’
and ‘E’ together can complete it in 20 days. If ‘E’ worked alone for 22 days and then left, how many days will ‘D’ take to complete the remaining work?Solution
Let the total work = 100 units {L.C.M of 50 and 20}
Then, efficiency of ‘D’ = 100 ÷ 50 = 2 units/day
Combined efficiency of ‘D’ and ‘E’ = 100 ÷ 20 = 5 units/day
So, efficiency of ‘E’ = 5 – 2 = 3 units/day
So, work done by ‘E’ alone in 22 days = 3 × 22 = 66 units
Remaining work = 100 – 66 = 34 units
Time taken by 'D' alone to complete the remaining work = 34 ÷ 2 = 17 days
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