There are 750ml of juice I drank 1/3 and my sister drank 2/5 of the total amount How many ml did my sister and I drink altogether

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.