Before you buy a ticket for tram/bus and you don't know if you just go for a short trip or the whole day use the "faitiq" app (link below).
In this app you track each ride for the day and the app will charge you the cheapest ticket for your rides at the end.
...sorry for my earlier post with the student ticket, I forgot that all the student benefits end with 27. I was in the same situation a "few" years back..but the student benefits "trick" works sometimes at smaller events in Linz so just try it it!
https://play.google.com/store/apps/details?id=com.fairtiq.android
Kenne zwei Alternativen, beide Android, beide kostentlos. Habe keine Ahnung bzgl. iPhone: