Question
Person 'A' can finish a task in 16 days by working
alone. Person 'B', who is twice as efficient as 'A', works on the task alone for 3 days. After that, Person 'A' joins 'B'. How much time will it take to complete the task?Solution
Let the total work be 16 units. So, efficiency of 'A' = (16/16) = 1 unit/day So, efficiency of 'B' = 1 X 2 = 2 units/day Work done by 'B' alone in 3 days = 2 X 3 = 6 units Time taken by 'A' and 'B' to complete the remaining work alone = {(16 - 6)/(2 + 1)} = (10/3) days So, total time taken to complete the work = 3 + (10/3) = (19/3) days
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