Party A and Party B completed a project in 12 days. Now the cooperation lasts for 4 days, leaving Party A 10 days, and Party B just finished it in 5 days. How many days does it take for Party A and Party B to do it alone?

There are three pipes, A, B and C. If A and B are on for two hours, the column will be full. A, b and c are all open, and the group is full in 3 hours. A can be on for five hours alone. Now fully open (A, B, C), after a while A will be closed, so fully open for 2 hours. Please find out when the three pipes are opened together.

Party A works alone in this project 10 day, and Party B works alone 15 day. If two people work together, the efficiency will be reduced, and Party A can only complete 4/5. Party B can only complete 9/65,438+00, and now it takes eight days. If two people cooperate as little as possible, how many days can they cooperate at least?

The cooperation between Party A and Party B is completed in 12 days, with Party A doing 3 days first and Party B doing 8 days, * * * 2/5. How many days will it take them to do it alone?

Two people cooperate for 4 days first, and then cooperate for 5 days. It is known that A is less than B every day 1/30. What do they need?