that's right, you have plenty of time, most lectures finish about 10 minutes early, that is they run 50 minutes each...some will run a but longer but you'll still have plenty of time. Tutorials don't start right on time either, tutors give students a bit of time to arrive and things like that...but really you'll have plenty of time, and most people in your tute will be coming from the same lecture, assuming it is for the same subject...so everyone will be moving from one to the other. Either way you don't have to worry, there is ample time for you to get where you need to so don't worry about that.