A project is completed in 15 days by team A alone. Team B does it alone to 12 days to complete, ?

1) 1 (1 15+1 12) is: the number of days A and B cooperate.

2) (1 15 + 1 12) 3 is looking for: the amount of work completed by A and B in 3 days.

3) (1-1 15 2) 1 12 asks for 2 days for A to do it, and B to do the rest for the number of days.

4) [1-(1 15+1 12) 2] 1 12 is the number of days required for B to do the rest after 2 days of cooperation between A and B.

5) [1-(1 15 3+1 12 4)] 1 15 is looking for: A does it for 3 days, B does it for 4 days, and the rest of A does it, the number of days needed.

If the total amount of work is 1, A can do 1 15 per day, and B can do 1 12 per day

1,1 (1 15+1 12)--The number of days required for A and B to cooperate to complete the project.

2, (1 15 + 1 12) 3 - 9 20 of the total amount of projects completed in 3 days of cooperation between A and B.

3, (1-1 15 2) 1 12--A does it alone for 2 days, and B does the rest alone, which takes a few days.

4, [1-(1 15+1 12) 2] 1 12--It is a few days after A and B cooperate to do it, and the rest will be completed by B in a few days.

5, [1-(1 15 3+1 12 4)] 1 15--A does it alone for 3 days, B does it alone for 4 days, and it will take a few days for A to complete the rest.

A for x days, (x 15) + (4 12) = 1Multiply 15, x+5=15, x=5,6,(1-1 Oak 12 4) 1 15 10 days.

B does 4 days and multiplies 4, and the rest is made by A, isn't it? Just use 1 to subtract the efficiency of A.

o( o ·2,(1-1 12 4) 1 1510 (day).

Team A did it alone for 10 days. , 0,1-(4 1 12) = 2 3 = remaining 2 3 1 15 = 10 days.

Hope, 0, a project, team A alone to do it to 15 days to complete, team B to do alone to do 12 days to complete now by team A alone after a few days, changed to team B alone to do 4 days just to complete the task.

1) 1 (1 15 + 1 12) The number of days of cooperation between A and B (2) (1 15 + 1 12) 3 is the amount of work completed in 3 days of cooperation between A and B (3) (1-1 15 2) 1 12 is the following

Liquid A is done for 2 days, and the remaining B is used for the mu bureau, and the number of days required (4) [1-(1 15+1 12) 2] 1 12 is A.

1. (1-4 10)*15=9 days.

15-4) 15 = 7 and 1 3 days.

3. The two teams can work together to complete the work of 1 10 + 1 15 = 1 6 every day, so 60% (1 6) = days.

4. Same as above, (1-4*1 number is positive 6) (1 15) = 5 days.

5. (1-4*1 6) (1 10) days.