That sounds about right the average number of machines. Most places you need to go around three times, sounds like a lot but it does go by quick. There is no set time of when have to start to excercise. You can go in at 10 past the hour, 20 past the hour etc. The location I go to has all the machines available so I only go around twice which works out to be 15 machines if I count correctly in my head.
I recommend giving it a try especially if it is free to try it out. I joined back in September and I still enjoy going. You can go as many times a week that you want and you can visit other locations. For the amount of money it ends up costing less than joining a health club.