Париж - passes, билеты, цены

[Foxus]

А на RER вы спокойно по Mobilis можете ехать до аэропорта, если он у вас на 1-5 зону.

Разве? Вот здесь пишут, что Мобилис не действителен на поезда до аэропортов:

I chose a Ticket Mobilis because I knew I’d have to make a same day round trip to Paris, with several Metro/RER rides while in central Paris. Thus the Mobilis makes the most economic sense and is also convenient, being a single ticket I use over and over, rather than multiple separate tickets I must keep track of. Keep in mind that Ticket Mobilis day passes are not valid for voyages to or from Airports CDG nor Paris-Orly.

http://parisbytrain.com/paris-train-ticket-machine/