If 5 men working 6 hours a day can complete a work in 20 days , in how many day s will 15 men complete the work working 8 hours a day ?

If 20 men working 7 hours a day can do a piece of work in 10 days, in how many days will 15 men working 8 hours a day do the same piece of work?

If 10 men can complete a work in 12 days . In how many days can 18 men complete the same work ?

If 15 men can complete a piece of work in 30 days, in how many days will 18 men complete it ?

7 men can complete a work in 52 days. In how many days will 13 men finish the same work.

10 men working 6 hours a day can complete a work in 18 days. How many hours a day must 15 men work to complete the same work in 12 days.