10 men and 15 women can complete a project in 12 days. If after 8 days, only \(\tfrac23\) of the work is completed, how many more women must be added to finish the work in the next 2 days, assuming all men continue?
35
Combined rate of 10 men and 15 women: \(10m+15w = \tfrac{1}{12}\) (project per day), using the standard assumption that one man's work equals two women's work (\(m=2w\)).
This gives \(35w=\tfrac{1}{12} \Rightarrow w=\tfrac{1}{420}\), so \(m=\tfrac{1}{210}\).
After 8 days, \(\tfrac23\) of the work is done (matching the planned rate exactly), leaving \(\tfrac13\) of the work for the next 2 days: required rate \(=\tfrac{1/3}{2}=\tfrac16\) per day.
With 10 men and \((15+x)\) women: \(10\times\tfrac{1}{210}+(15+x)\times\tfrac{1}{420}=\tfrac16\).
Solving: \(\tfrac{20+15+x}{420}=\tfrac16 \Rightarrow 35+x=70 \Rightarrow x=35\).
Hence, 35 more women must be added to finish the work in the next 2 days.
A and B can do a piece of work in 18 days. B and C together can do it in 30 days. If A is twice as good a workman as C, find in how many days B alone can do the work?
Two men and 7 women can complete a work in 28 days, whereas 6 men and 16 women can do the same work in 11 days. In how many days will 5 men and 4 women, working together, complete the same work?
A man and a woman, working together can do a work in 66 days. The ratio of their working efficiencies is 3 ∶ 2. In how many days 6 men and 2 women together can do the same work?
Each one of five men independently can complete a work in 20 days. The work is started by one person. Next day one more person joins and every next day one more person joins. From the fifth day, five persons continued working as a team. In how many days, will the work be completed?
Numan does half the work as Gagan in 4/5 of the time. If together they take 16 days to complete a piece of work, then how long will it take Gagan to complete the work?