15 men can do a work in X days. 20 women can do the same work in 2X days. 57 women can do the work in 20 days. In how many days 9 men can do the same work.

8 men and 3 women can do a piece of work in 7 days, whereas 5 men and 1 woman can do it in 12 days. How many men should assist 8 women so that the same work is completed in $$4\frac{1}{5}$$​ days?

A work can be completed by x persons in 50 days. Due to absence of 5 persons, the work was completed in 55 days. The value of x is

9 men can complete a piece of work in 8 days, while 4 women can do it in 9 days. In how many days can 2 women and 4 men complete this work?

4 men can complete a piece of work in 10 days, while 3 women can do it in 16 days. In how many days can 6 women and 5 men complete this work?