How do you do?
 From CDG to Station Edgar Quinet, I will take RER B from CDG to Station Denfert-Rochereau first, and then transit from this station to Station Edgar Quinet. My question is whether or not I should buy a new ticket from Station Denfert-Rochereau to Station Edgar Quinet.
 I also want to inquire Navigo Pass. Can I take Navigo Pass from Station Edgar Quinet to Château de Versailles?
- You'll use the same RER ticket when transferring off RER B onto a local Paris Metro line in Paris, regardless of which one. If you need to take another RER after RER B, that would require another ticket or a custom-made ticket good for the entire trip.
- Yes, Navigo Découverte will be good for any Metro station in Paris out to Chateau de Versailles. Keep in mind that Navigo is strictly Monday till Sunday and you cannot buy it / use it fur the current week from Friday morning onwards.