Transilien (SNCF) trains in Paris

The trip from Clamart to Paris cannot be done on the single 1.90€ ticket. That is for the metro, buses, trams and the RER trains -- in the case of the RER trains for travel within the city. You would take the N line to Paris using a ticket for that and then begin your travel within Paris on the metro using a different type of ticket. The ticket from Clamart to Paris costs 2.80€ for a single ticket or 22.40€ for a carnet (booklet of ten). As you know a regular metro ticket costs 1.90€ or 14.90€ for a carnet. I have been told that you could load a Navigo day pass on to the Navigo Easy and that it would be 7.50€ per day plus the 2€ for the Navigo Easy, but I have never done it and have no idea. I am not sure if you can load a bunch of days or just one at a time. Unless you can load a bunch of day passes at one time, I don't see what the benefit would be of having the Navigo Easy.

To get to Versailles Palace from Clamart, you could take the "N" to Viroflay Rive Gauche and change to the RER to Versailles Rive Gauche, or just stay on the "N" to Versailles Chantier and take a bit longer walk to get to the palace.

JHK's advice is not quite accurate: the ticket from Clamart to Paris would also be valid for a trip on the metro, same on the way back. NOT for a trip on buses (go figure). This doesn't change much to the overall equation: a Navigo Découverte will be worth it, if your trip falls more or less between a Monday and a Sunday.

I apologize for providing incorrect information. This summer I had to go from Bastille to Bellevue and the transit worker told me that my Metro ticket would not be good for the trip. His advice was to take the metro to Montparnasse and then buy a Transilien ticket there and same for the return. I thought that was the rule but I now realize (thanks Balso) that I was probably told to buy a ticket for the Transilien because I already had metro tickets.

Thank you everyone! That helps to clear things up for me!

@JHK
I had not realized that I could buy a carnet for my 2.80€ trip as well. I had read about the carnet for the T+, so I thought it was only for the 1.90€ tickets. This is fantastic to know because I will not be making 10 trips, but now I can share the carnet between my husband and I.
I found this site which says that I can load 2 day passes on the Navigo Easy. But knowing about the carnet, I think that is probably the best way to go for us. Thanks for your help!

NavigoEasy is taking the carnet electronic. Instead of 10 cardboard tickets, the carnet package will be installed on you NE electronic card. Same price per trip (once the card itself is purchased for a small sum; it is easily recharged). And it is indeed easy to use; just tap and push through the open gate. The card can also carry some passes. I suggest looking up the details on the RATP site.:
https://www.ratp.fr/en

Thanks, but I think the downside to adding the carnet to the Navigo Easy is that I won't be able to split the 10 tickets between my husband and I? I won't be making 10 trips, but between the two of us, we will be. If I could put 5 trips on his Navigo Easy and 5 trips on mine, then the pass may be more convenient overall I think.

If you don't do Découverte, you'll need paper tickets anyway for Clamart to Paris and vice versa, so I'd just buy two carnets: 10 Paris "t+" tickets, for transportation within Paris, and 10 Paris-Clamart tickets, valid from any metro station in Paris to Clamart (and vice-versa).
For example:
- Clamart to Trocadero = 1 Paris-Clamart ticket, that you use both on the suburban Transilien train to Montparnasse and on the metro
- Trocadero to Louvre = 1 "t+" ticket
- Louvre to Clamart = 1 Paris-Clamart ticket, that you validate once to get into the metro, and again at Montparnasse to get to the train, and finally upon exit at Clamart.

@Balso

Many thanks for the detailed explanation!

By the way, can I buy my tickets (point to point, and pack of 10, day passes) online before my trip? I read that at the ticketing machines, they only take coins. What if I only have bills?