how old do you have to be to apply at most fast food restaurants?

[bayonet897]

I'm going to be turning 15. I was wondering how old you have to be to apply for a job at fast-food restaurants like mcdonalds and burger king. I know these are the only places that would probably accept 15 year olds working there. If you have to be like 17 to work there then how old would you need to be to apply at a movie theatre?