u/Upbeat-Morning-5788

https://www.viator.com/tours/Paris/Paris-Latin-Quarter-Free-Walking-Tour/d479-394285P14

We found this Viator tip based walking tour online and had a couple questions about it. The itinerary lists almost 15 places with 10 minute stops at each location but how does that allow enough time to actually visit the site? All of the locations state that the admission ticket is free but that doesn't seem quite right either like for Musee de Cluny and Pantheon. Should tickets actually be purchased ahead of time if attending this tour?