How do you tell the possible rational roots of a polynomial function? How do you test one of the possible rational roots to see if it is indeed a zero?

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.