Volunteer a plans to complete a certain work in the community in several working days. From the third working day, volunteer B joins in the work, and the work efficiency of both Party A and Party B is the same. As a result, the task is completed 3 days in advance, the number of days that volunteer a plans to complete the work is () A. 8B. 7C. 6D. 5

Volunteer a plans to complete a certain work in the community in several working days. From the third working day, volunteer B joins in the work, and the work efficiency of both Party A and Party B is the same. As a result, the task is completed 3 days in advance, the number of days that volunteer a plans to complete the work is () A. 8B. 7C. 6D. 5

Suppose volunteer a plans to complete this work in X days, so the work efficiency of both Party A and Party B is: 1 x, Party A has completed 1 x × 2 in the first two working days, and has completed 1 x (x − 2 − 3) and 1 x (x − 2 − 3) in the remaining working days, then 2x + 2 (x − 2 − 3) x = 1, and the solution is x = 8

Volunteer a plans to complete a certain work in the community in several working days. From the third working day, volunteer B joins in the work, and the work efficiency of both Party A and Party B is the same. As a result, the task is completed 3 days in advance, the number of days that volunteer a plans to complete the work is ()
A. 8B. 7C. 6D. 5

Suppose volunteer a plans to complete this work in X days, so the work efficiency of both Party A and Party B is: 1 x, Party A has completed 1 x × 2 in the first two working days, and has completed 1 x (x − 2 − 3) and 1 x (x − 2 − 3) in the remaining working days, then 2x + 2 (x − 2 − 3) x = 1, and the solution is x = 8