P and Q can individually do some work in 60 and 75 days respectively. They started working together. But P left after sometime. Q completed the work in another 30 days. In how many days after starting the work did P leave?

A and B can finish a piece of work in 15 days and 20 days respectively. If A and B work on alternate days (A starts the work), how many days will it take to complete the work?

A, B, C and D can do a piece of work separately in 30 days, 33 days, 36 days and 44 days, respectively. In how many days can A and B together complete the work, if A and B together are assisted by C and D on alternate two-two days starting with C for first two days, then D on next two days and again C on next two days and so on?

Parth, Rizwan and Sangeeta can do a piece of work in 40, 60 and 80 days. Parth works daily, but Rizwan & Sangeeta assist him every 3rd day. In how many days will the work be done?

P, Q, R and S can complete a piece of work in 25 days, 30 days, 36 days and 40 days, respectively. They work on a rotation basis with Q working on the first day, S on the second day, P on the third day and R on the fourth day, then again Q on the fifth day and so on. In how much time will the work be completed?

Avi can finish a piece of work in 6 days, Avni can finish it in 8 days, Aarti can do it in 12 days and Reeta can do it in 16 days. They all decided to work one by one, Avi starts the work and works for one-fourth of a day, then Avni works for one-fourth of a day, then Aarti works for one-fourth of a day and then Reeta works for the remaining one-fourth of a day. The cycle is repeated till the work finished. Who was working when the work finished?

A, B and C can do a piece of work in 22 days, 24 days and 33 days, respectively. In how many days will the work be finished if, A works on the 1st day, C works on the 2nd day, B works on the 3rd day, A works on the 4th day and so on?

A, B and C can do a piece of work in 15 days, 30 days and 40 days, respectively. A starts working on the first day, A and B works on the second day and A and C works on the third day. This pattern is repeated till the work gets completed. In how many days will the work be over?

A, B, C and D, working separately, can do a piece of work in 5 days, 6 days, 8 days and 10 days, respectively. In how many days can A and B complete the work together, if they are assisted by C and D on alternate days, starting with C?