Question
20 boys working 9 hours a day can
finish a task in 12 days. They all worked together initially, but after 10 days, 5 boys left. How long will it take for the remaining boys to finish the leftover work?Solution
ATQ, Let the efficiency of each boy be 'b' units/hour Therefore, total work = 20b X 9 X 12 = '2160b' units Amount of work completed in first 10 days = 20b X 9 X 10 = '1800b' units Remaining task = 2160b - 1800b = '360b' units Since, 5 boys left the task, therefore Time taken by 15 men to complete the remaining work = (360b/15b) = 24 hours
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