1. A can complete a piece of work in 16 days and B in 24 days. In what time they complete if they work together?
Ans: 9.6 days
2. A tap can fill a cistern in 8 minutes and another can fill it in 12 minutes. If both are opened simultaneously, find the time that the cistern will be full.
Ans: 4.8 min
3. If a pipe fills a tank in 15 minutes and a leak in the bottom empties it in 25 minutes, when both function simultaneously then in what time can the tank be filled?
Ans: 37.5 min.
4. A can reap a field in 8 days while A and B together can reap the same field in 6 days. In how many days will B alone can reap that field?
5. 32 men can do a piece of work in 18 days. In how many days can 36 men do that work?
Ans: 16 days
6. Two pipes A and B can fill a tank in 4 and 5 hours respectively. A drain pipe C can empty a full tank in 8 hours. In what time can the tank be filled when all the three are open simultaneously?
7. In a garrison, provision is sufficient for 600 soldiers for 15 days. But after 5 days 100 soldiers left the garrison. For how many days more the provision last for them?
Ans: 12 days
Total number of mandays = 15× 600 = 9000
Number of mandays completed = 5 × 600
Remaining mandays = 9000 − 3000 = 6000
Number of soldiers = 600 − 100 = 500
Number of days provision last = = 12 days
8. Ravi can do a work in 20 days. He worked alone for 10 days and the remaining work was completed with the help of Hari in 2 days. In how many days will the total work be completed if they work together?
Ans: 4 days
9. A pipe can fill 80% of the cistern in 12 minutes. In how many minutes it can fill half of the cistern?
Ans: 7.5 minutes
10. A contractor employs 15 men to complete a work in 10 days. But after 8 days he notices that only 60% work has been finished. In order to finish the work in the stipulated time, how many more men are required?
11. A pipe fills a tank in 5 hours and a leak empties in 4 hours. When both function simultaneously, in what time can the tank be emptied?
Ans: 20 hours
12. 16 men can do a piece of work in 12 days. 5 days after they started the work, 4 more men joined them. How many days will they now take to complete the remaining work?
Ans: 5.6 days
Explanation: Total mandays required for the work = 12 × 16 = 192
Number of mandays completed in 5 days = 5 ×16 = 80
Remaining mandays = 192 − 80 = 112
Number of men available now = 16 + 4 = 20
Number of days required = = 5.6 days
13. A can build a wall in 18 days, B in 12 days and C in 15 days. In how many days will the wall be built if all the three work together?
14. A can do a piece of work in 40 days. He worked at it for 5 days after that B finished it in 21 days. In how many days can A and B together finish the work?
Ans: 15 days