Question
28 men and 21 women can complete a work in 16 days. All
of them start working together and after working for 12 days the women stopped working. All men alone complete the remaining work in 8 days. How many days will it take for completing the entire work if only 21 women are employed on the job?Solution
28 men and 21 women can complete the work in 16 days.  ∴ Work done by them in 12 days = 12/16 = 3/4  Remaining 1-3/4 = ¼ work is completed by 28 men in 8 days.  => Time taken by only 28 men to complete the whole work = 4 x 8 = 32 days.  Work done by 21 women in a day = 1/16 – 1/32 = 1/32  ∴ Time taken by 21 women to complete the work = 32 days
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