15 boy and 12 girls together can complete a work in ‘a’ days while 5 boys and 22 girls can complete the same work in ‘c’ days. Ratio of efficiency of a boy to a girl is 2: 5. Find the possible value/s of a + c where a and c are positive integers.
(I) 18
(II) 8
(III) 28
(IV) 14
(V) 21

25 persons, each working 10 hours a day, can complete 2 units of work in 4 days. How many days will it take for 10 persons working 9 hours a day to complete 18 units of 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?

To finish a work in 8 days, 10 men are required, or 15 women are required. If 'x' men and 'y' women are required to finish the work in 12 days, then which of the following equations is correct?

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?

6 men can complete a piece of work in 9 days, while 6 women can do it in 6 days. In how many days can 2 women and 3 men complete this work?