P₁ alone can do $${2\over 3}$$  of the work in 8 days. P₂ alone can do $${7\over 12}$$  of the work in 14 days. P₃ alone can do $${8\over 15}$$   of the work in 16 days. In how many days can they complete the work, if all three work together?

If A works alone, he would take 4 days more to complete the job than if both A and B worked together. If B worked alone, he would take 16 days more to complete the job than if A and B work together. How many days would they take to complete the work if both of them worked together?

To do a certain work, the ratio of the efficiencies of A and B is 7: 5. Working together, they can complete the same work in $$17{1\over 2}$$ days. A alone will complete 60% of the same work in:

A can do a work in 12 days while B can do the same in 20 days. If A work for ‘x’ days while B work for ‘x+4’ days then one-third of the work is complete. Find the value of x.

 ‘A’ can complete a work in 20 days while B is 25% more efficient than ‘A’. B worked for 6 days and left, the remaining work is completed by ‘C’ in 15 days. Find how many days ‘C’ can complete the whole work alone. 

Three pipes A, B can fill the tank in 12, 20 hrs respectively and C can empty the tank in 30 hours. If the pipes are opened alternatively for 1 hour starting with A and drain pipe is kept open all the time. How much time will it take to fill the tank.

A alone can complete a work in 25 days and B alone can do the same work in 20 days. A started the work and after working 7 days B joined A to finish the remaining work. In how many days, the total work will be finished?

A is 50% more efficient than B. They together start the work and $$ {7\over 12}$$ th of work is left after 8 days. Find in what time B alone will complete the whole work.