It varies greatly depending on seniority, the company you work for, the airline your company supports (IE which "express" you fly under), the type of trips you desire (multi-day vs standup vs day trips), and where you are based from. There's no simple "equation" that creates a typical trip.

For your reference, I pulled up some old flight pairings/schedules that I flew when I was working at Atlantic Coast Airlines (Flying as United Express). They might give you a bit of insight as to what a typical work week might look like.