Time and Work Questions

Smita can finish a work in 12 days and Sam can finish the same work in 9 days. After working together for 4 days they both leave the job. What is the fraction of unfinished work?

X is 25% more efficient than Y. If Y alone can make a chair in 10 days, then X alone can make the chair in how many days?

M can complete 3/4 part of a work in 12 days and N can complete 2/7 part of the same work in 8 days. In how many days will both complete 11/14 part of the total work?

P and Q together can make a door in 12 days. They started the work together but after 8 days P left the work. The remaining work is completed by Q alone in 7 more days. In how many days can P alone complete the entire work?

30 women do half of the total work in 30 days. How many more women will be required to complete the remaining work in 10 days?

P alone can do a piece of work in 8 days and Q alone can do the same work in 10 days. In how many days will both together complete the same work?

Parvesh is three times as efficient as Dinesh. Parvesh takes 20 days less than Dinesh to complete a book. If both of them work together, then in how many days the book will be completed?

X and Y together can do a piece of work in 30 days. Y and Z together can do the work in 20 days. X starts the work and works for 15 days then Y takes that work and works for 27 days. Finally Z finishes the remaining work in 9 days. In how many days Y alone can complete the entire work?