Validity of t+ tickets.

If they are just regular old Metro +t tickets, then the answer is no. Since the fare is more than the standard 1.90 EUR, you need to purchase separate IDF point-to-point tickets to and from. Its 3.65 EUR each way for Versailles, and 10.30 EUR for CDG.

You could use +t tickets on the 350 bus to CDG from Gare de l'Est bus depot. I believe 3 tickets is the fare.

No. A t+ ticket is basically Paris city only. It is valid on the whole of the métro (including the ends of lines outside Paris), but on the RER only within Paris. If you look at the métro map here: https://www.ratp.fr/sites/default/files/plans-lignes/Plans-essentiels/Plan-Metro.pdf you will see a sort of flattened "S" marker on the RER lines just outside the city boundary, that is the limit for t+ tickets.

Beyond that point (for example Versailles or CDG airport) fares are based in distance. From memory Paris (any métro station) to CDG is €10.50, I don't know the fare for Versailles. You can bus these tickets to suburban destinations at any métro station.

Regular old metro t+ tickets???

Is there something like a new t+ ticket too? Pardon my ignorance
So as I understand..... if I buy the cartel..... would still need to buy fresh tickets to and from Versailles and to the airport too!

By "regular old +t tickets" I meant for standard in-Paris transport. Carnets of 10 tickets are available for any price trip. For instance, if you had 5 people going to Versailles and back, you could buy a "carnet" for 29.20 EUR, so each person would be paying 2.92 EUR each way rather than the standard 3.65 fare.

Paris Metro tickets are by zone. Your tickets apply only to the city zone, which is rather broad but does not cover more far flung destinations like Versailles or CDG. You'll have to buy specific tickets for those. And a warning, you can get on a central Paris RER with your standard ticket, and ride in the city. But if you attempt to ride all the way on those tickets, you'll be fined at the destination.

. I wouldnt dare to do any such thing. But Thanks for that note Douglas

Paris Metro tickets are by zone.

With a few rare exceptions, tickets are not sold by zone. Passes are sold by zone.

Paris Metro tickets are by zone.

With a few rare exceptions, tickets are not sold by zone. Passes are
sold by zone.

Perhaps a clarification is needed - most areas of the Paris Metro can be used on a regular ticket. But those tickets do not apply to zones outside the city, especially the RER's that travel to suburbs. Those areas are most definitely zoned. Since the OP's question was about Versailles and CDG, my answer was in response to that.

no tickets are sold by zone. Metro tickets are good on the metro regardless of zone; some metros are in zone 3. The same tickets are good however on the RER ONLY within zone 1 Paris. For travel outside Paris you don't buy a ticket by zone but by specific station e.g. Paris to Versailles Rive Gauche. or Paris to CDG. If you use a ticket to a destination in say zone 4 and then decide to walk to another destination in zone 4 e.g. a stroll along the river to the next town, then you will not be able to use the ticket back to Paris because it is for that particular station in zone 4 not all of zone 4. I learned this the hard way.

Passes like the overpriced Visite, the sometimes useful Mobilis or the cost effective Navigo Decouverte are sold by zone although in the case of the ND any pass that includes Paris includes all 5 zones.

most areas of the Paris Metro can be used on a regular ticket.

There are two types of single ride tickets: the T+ or a ticket origine-destination. The ticket jeune weekend is a day pass and not really a ticket in spit of its name. I have never heard of a regular ticket nor have I ever seen one for sale at a ticket kiosk.

The T+ is valid for travel on the métro, bus, funicular, tramway or within Paris on the RER.
The ticket origine-destination is valid for travel between two points, at least one of which is outside of Paris. Zones have absolutely nothing to do with the price or validity of a ticket origine-destination.,

Those areas are most definitely zoned.

The zones you mention apply to the cost of passes, not tickets.

Navigo Decouverte are sold by zone although in the case of the ND any pass that includes Paris includes all 5 zones.

This is an often quoted misconception. Navigo fares can include all zones 1 to 5 but they are also available and sold for zones 2 to 3, 3 to 4, and 4 to 5. If you want a zone 1 to 5 fare, you must specifically ask for a zone 1 to 5 fare.

Any ND that includes Paris will include all 5 zones. Since you charge them on a machine, you of course select the 5 zone choice that includes Paris. Passes that include only zones 4-5 or whatever do not include Paris. IN times past you could buy a ND for zones 1-2 or 1-3 etc. That is no longer the case. Any ND charge that includes Paris includes all 5 zones.