Carpenter A can make a chair in 6 hours, carpenter B in 7 hours and carpenter C in 8 hours. If each carpenter works for 8 hours per day, how many chairs will be made in 21 days?

If 4 men or 6 women can do a piece of work in 12 days working 7 hours a day. How many days will it take to complete a work twice as large with 10 men and 3 women working together 8 hours a day?

10 women can complete a work in 7 days and 10 children take 14 days to complete the work. How many days will 5 women and 10 children take to complete the work?

Two persons A and B complete a task in 15 days, when they work together. Person A completes the task in 20 days if he works alone. How many days will B take to finish the task alone?

If A and B can finish a work in 10 days, B and C can finish the same work in 12 days, C and A can finish the same work in 15 days; then in how many days can A, B and C together finish half of the wor…

If 25 men can reap a crop in 60 days, then in how many days will 10 men reap the crop?