Every yellow marble is expensive. One-half the orange marbles are expensive. One-half of all expensive marbles are yellow. There are 40 yellow marbles and 25 expensive marbles that are neither yellow nor orange. How many orange marbles are there?

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.