Given the functions a(x) = 3x − 12 and b(x) = x − 9, find a[b(x)]. Show your work.

Mahnoor randomly selects times to walk into a local restaurant and observe the type of music being played she found that the restaurant was playing country 11 times rock & roll 17 times and blues 8 times use the observed frequencies to create a probability model for the type of music the restaurant is playing the next time mahnoor walks in.