27. 15 people completed a work in 7 days 10 How many days should people take to complete this work?

15 persons working 8 hours a day can complete a work in 21 days.How many days will 14 persons take to complete a work 1(1)/(2) xx as great,if they work 6 hours a day?

15 persons can do a piece of work in 12 days. How many more people are required to complete the work in 10 days?

If X and Y can complete a piece of work in 15 days, and X alone can do the same work in 30 days, find how many days will Y alone take to complete the same work?

13.A and B together can do a work in 25days. They work to together for 15days and then B leaves.A finishes the rest of the work in 20 days.How many days would each take to complete the work seperately?