It depends on what sport you are referring too. There are 235 Division I college football teams. 119 in the FBS, 116 in the FCS In basketball, there are 341 teams. And it varies for other sports.
I believe several things factor towards what division a school plays in. One i think it depends on the size like ifs a very large school good chance its a D.1 school. IT also has to do with the...