Passage

Directions: Read the data carefully and answer the following question. David, John, Mike, and Sam are four workers who together can complete a project 'P' in 9 days and Sam did the one fifth of the project P. The efficiency of David is five times that of Mike, while John's efficiency is 100% more than that of Mike. Also, Mike and David working together can complete the project 'P' in p days, while Mike and Sam working together can complete the project 'P' in y days.

If r men can complete the project in (p + 15) days, while (y - 20) men can complete the same work in n days. If (y - 25) men can complete the same project in (n + 9) days, then in how many days can (n - r + 3) men can complete the project?