Can I run 2 different updates of FCPX on the same computer?

How can I run 2 versions of FCPX (update 10.1.1 and the original FCPX) on the same computer?

I'm working on a team using FCPX. Recently, my computer updated FCPX to 10.1.1 (I'm assuming bc I have a newer computer & OS). The others on the team have FCPX, the earlier version.

Because we have projects edited on both version of FCP and we need to be able to transfer projects from one computer to another, I need to be using the earlier version of FCPX. However, I also need to be able to edit the 10-15 projects we've started in 10.1.1. So, I'm looking to somehow run the 2 different versions of FCPX on a single computer.

How could I best accomplish this - thru different users? partitioning the drive? Any suggestions??