Aria is a songwriter who collects royalties on her songs whenever they are played in a
commercial or a movie. Aria will earn $20 every time one of her songs is played in a
commercial and she will earn $80 every time one of her songs is played in a movie.
Aria earned a total of $400 in royalties on 11 commercials and movies. Determine the
number of commercials and the number of movies on which Aria's songs were
played.