An English class of 18 students is going to put on a play with 18 positions available. Positions are being selected by random selection. What is the probability that Cody will be picked for Sound System, Mellissa for Scenery, and Nicholas for Lighting?

Your vet has placed your pet on a diet. the diet is to contain at least 12 mg of fat and at least 14 mg of protein per serving. these requirements are to be obtained from two food sources. source a contains 2 mg of fat and 2 mg of protein per serving. source b contains 1 mg of fat and 3 mg of protein per serving. if source a sells for $1.28 per serving and source b sells for $1.12 per serving, how many servings of each type should be purchased to satisfy the requirements at minimal cost?