what type of fare media is used and how much it is to ride on the marc?
Fares are issued on paper tickets in either one way, 10-trip, weekly, or monthly increments. You can also purchase monthly tickets that double as Washington Metro Farecards, although I'm note entirely sure how one goes about that.
Fares vary by distance travelled; it's not a flat fare. You can find the fare chart at:
http://www.mtamaryland.com/services/mar ... /fares.cfm
-Rafi