Laborer A can finish a piece of work in 12 days, and Laborer B in 18 days. Laborer C can undo the work in 36 days (he spoils it instead of building). All three start together. After 3 days, C stops working. After 2 more days, A stops working too, and only B continues until the work is finished.

A, B, and C can do a piece of work in 24, 30, and 40 days respectively. They work in turns: A on the 1st day, B on the 2nd day, C on the 3rd day, then again A on the 4th, and so on. However, A is sick and does only half of his usual work whenever it’s his turn.

A can do a piece of work in 12 days, B in 15 days, and C in 20 days.

They work together for 2 days, after which A leaves. B and C then

work for 3 days, and then B leaves. Finally, C completes the

remaining work alone in 5 days. In how many days would C alone have

completed the entire work?

A contractor employed 30 men to complete a piece of work in

24 days. After 18 days, he found that only half the work was

done. How many more men must he employ so that the work

may be finished in time?

A and B can do a piece of work in 30 days and 40 days
respectively. They begin together, but A leaves 5 days
before completion. If B worked alone during the last 5
days, then the total number of days taken to finish
the work is:

X, Y, and Z can complete a piece of work in 20, 25, and 30 days respectively. They work in turns: X on the 1st day, Y on the 2nd, Z on the 3rd, then again X on the 4th, and so on. But Z is lazy and does only two-thirds of his usual work whenever it’s his turn.

In how many days will the work be finished?

X can do a work in 18 days, Y in 27 days. They work together, but every 5th day, X rests. In how many days is the work done?

Worker A can complete a job in 12 hours, Worker B in 16 hours. Worker C can undo the work in 20 hours.

All three work together for 3 hours, then Worker C stops and only A & B continue.

Find the total time to finish the job.