@helena We did a trip like that, plus we also added Dilijan 😆 but honestly — it’s madness, a total whirlwind tour.
We wanted to do it all in one day… Thinking about it.
Is it possible to visit all of these in one excursion:
Hello!
It’s possible in one day, but it will be difficult, you’ll get tired and the quality of your impressions may suffer.
I would split it up.
From Yerevan it’s logistically convenient to visit (with an early departure): Charents Arch + Garni + Symphony + Geghard + Azat Reservoir. Adding Sevan (Sevanavank) would be a bit of an overload, although there you could at least properly relax and have dinner after all those locations 
And on the second day I would go in another direction: Khor Virap, and then through the stork village of Surenavan — to Noravank. It’s very beautiful there)