College Majors Question?

I am planning to transfer to a University from Community College soon, and I would like to attend UC Berkeley or UC Irvine, which both have business majors. I noticed that they only let a certain number of people to a major.... so if every major was full, would that mean that I have to spend more time in college? If the business administration major is only allowing 150 people, then is there no way for me to major in business? It doesn't make sense.