(1) If 1 person completes 1 project in 0 days, then the project is planned to be completed by 40 people in 15 days, and it can be found that there are 40 * * 15 = 600 projects.
(2) If we need to finish the project within 12 days and need to do 600/ 12=50 (copies) every day, then we need to increase 50-40= 10 (people).