1. There is a project, which will be completed by Team A in 40 days and Team B in 60 days. Now we know that the project was completed by two teams, but the middle team A was transferred for a few days because of other tasks, so it took 27 days to complete all the work, and the team A walked for a few days.

2. The master and the apprentice work together to process a batch of parts. The master works alone for 15 hours and the apprentice works alone for 20 hours. If we work together, the master will make 80 more parts than the apprentice when the task is completed. How many parts are there in this batch?

3. To build a highway, it takes 8 days for Team A to repair it alone, 12 days for Team B, and 6 days for Team C. Now Team A and Team B jointly repair it for two days, and the remaining teams continue to repair it. How many days will it take?

The water tank is equipped with two water injection pipes, A and B, which can fill the whole water tank in 20 minutes. Now the two pipes are filled with water for 2.5 minutes at the same time, filling up 5/24 of the water tank. How many minutes does it take to fill the water tank if the B pipe is opened separately?

5. Two crabs and four shrimp soldiers can clean 3/65,438+00 Dragon Palace, and eight crabs and 65,438+00 shrimp soldiers can clean the whole Dragon Palace at the same time. If only crabs are allowed to clean and only shrimp soldiers are allowed to clean, how many shrimp soldiers will clean the whole Dragon Palace?

6. It takes 10 days for group A, 12 days for group B, and group C can produce 64 toys every day. If Party A and Party B cooperate for 4 days, there are still 256 unfinished items. Now we have decided that three groups will make these toys. How many days will it take?

7. The school has a four-story teaching building with six classrooms on each floor. There are three doors (two front doors and a side door of the same size) in and out of the building. The door was inspected during the safety inspection; When a main entrance and a side door are opened at the same time, 400 students can pass through in 2 minutes. If a main entrance can pass 40 more students per minute than a side door, how many students can pass through a main entrance and a side door per minute?

8. For a project, it takes 15 days for team A to do it alone, 20 days for team B and 12 days for team C to do it alone.

(1) What fraction of the project is completed by each of the three teams every day?

(2) How many days does it take for three teams to cooperate to complete the project?

(3) How many days does it take for three teams to cooperate to complete the project?

(4) How much will Party A and Party B pay back after 3 days of the remaining works?

(5) How many days does it take for three teams to cooperate to complete the project?

(6) After three teams cooperate for two days, the rest will be done by Team A alone. How many days will it take?

(7) After two days, the rest shall be completed by both parties. How many days will it take to complete?

(8) How many days will it take for Team A to work for three days, and the rest will be completed by three teams?

(9) After Party A and Party C work together for two days, the rest will be done by Team B alone. How many more days will it take?

9. It takes 15 days for a project to be completed by Party A alone, and days for Party B to complete it alone. Now Party A will do it for a few days, and then both parties will do it together.

All this was done in a few days. How many days did A work alone before A and B joined hands?

10. Party A, Party B and Party C completed a project within 8 days. Now Party A and Party B cooperate 1 day, and the rest is done by Party C alone 15 days. In order to improve the efficiency of the solution.

1 1. A reservoir has two water pipes. The outlet pipe 10 minute can fill the whole pool, and the outlet pipe 15 minute can drain the whole pool. How many minutes can the whole pool be filled when two pipes are opened at the same time?

12. It takes 8 hours for the local train to go from Station A to bilibili, and 6 hours for the express train to go from bilibili to Station A. The two trains are running in opposite directions. It takes two hours for the local train to leave from Station A, several hours for the express train to leave from bilibili, and several hours for the express train to meet the local train.

13. The express train takes 8 hours from city A to city B, and the local train takes 12 hours from city B to city A.. Two trains leave from two directions at the same time. When they met, the express train was longer than the local train 180 km. How many kilometers are the two stops apart?

14. For a manuscript, if Party A types this manuscript every hour, it will take Party B four hours to finish it alone. If two people type this manuscript together, how many hours can it be completed?

15. It takes 40 days for Team A to complete a project, and the ergonomics of Team A belongs to Team B. If the two teams cooperate, how many days will it take to complete the project?

16. To build an expressway, it will take 8 days to repair the perfect armor, Party B 10 days, and both parties will work together for 4 days, with 72 meters left to be repaired. What is the total length of this highway?

17. A project will be completed by Party A for 75 days and Party B for 50 days. During the joint work, Party A left for a few days and the whole project was completed within 40 days. How many days did Party A walk halfway?

18. For a batch of goods to be delivered separately, Party A needs 10 hour and Party B needs 15 hour. After a period of time, Party A will deliver the goods first, and then Party B will deliver them. How many hours did it take to ship all the goods?

19. It takes 12 hours to type a manuscript together and 20 hours to type a manuscript alone. Now two people are typing together until the task is completed. A has typed 9000 more words than B. How many words are there in this manuscript?

20. A project will be completed by itself in 20 days and 30 days. Now it's done by two people, with a rest 1 day in the middle and b rest for 6 days. How many days did they work at the same time when the project was completed?

2 1. A slender candle is lit in 4 hours, and a short candle is lit in 6 hours. After two candles are lit at the same time for 2 hours, the remaining length is exactly the same. How much is the stubby candle?

22. The pool is equipped with water inlet pipe and drainage pipe. Open the inlet pipe for 4 minutes to fill the pool with water, and open the drain pipe for 6 minutes to empty the pool. There is 1/3 dirty water in the pool now. Li Shifu had to drain the dirty water first, but he forgot to turn off the drain when he drained the clean water. How long does it take to fill up the clear water?