Public transport : which ticket to buy

To travel on the Paris transport network, you have two options: 
- Purchase an Easy Navigo pass (rechargeable card for €2) valid for the duration of your stay. You can purchase this card at the ticket office or from ticket machines.
-Purchase your tickets on your smartphone (if your smartphone is equipped with NFC technology) via the app: https://www.iledefrance-mobilites.fr/application. 

To come to the campus you must take :

If you come by airport : an airport ticket (be careful you must pay separatly go and back ticket)  + a bus ticket

If you come by train : a RER/metro ticket + a bus ticket