A can do a piece of work in 12 days. When he had worked for 3 days. B joined him. If they complete the work in 3 more days, in how many days can B alone finish the work? 

A can paint a house in 55 days and B can do it 66 days. Along with C, they did the job in 12 days only. Then, C alone can do the job in how many days?

Ramesh can do a work in 21 days and Mahesh in 42 days. If they work on it together for 7 days, then what fraction of work is left?

Some persons can do a piece of work in 12 days. Two times the number of such persons will do half of the work in 

P and Q together can do a job in 6 days. Q and R can finish the same job in 60/7 days. P started the work and worked for 3 days. Q and R continued for 6 days to finish the work. Then the difference of days in which R and P can complete the job alone is 

A is twice as efficient as B in writing novels. Together they can complete the task of writing a novel in 24 days. In how many days can A write the novel alone?

If 20 women can lay a road of length 100m in 10 days. 10 women can lay the same road of length 50m in: 

A and B can do a piece of work in 28 and 35 days respectively. They began to work together but A leaves after sometime and B completed remaining work in 17 days. After how many days did A leave?