Please excuse me for not trawling through all the previous threads for this specific information.
I will be in Paris for 4 nights, travelling back out to CDG airport on the MONDAY.
During my stay, I wish to visit the city tourist sites (making use of the Metro where possible) but also take a trip out to Versailles.
I have briefly read about the Navigo Decouverte which appear to run Monday - Sunday.
What, therefore, would be my best / cheapest options for my journeys during my stay?
There are two of us travelling together.