Abag contains 20 apples, of which 5 are bruised. peter picks up an apple and realises it is bruised. he puts the apple back in the bag and picks another one.
a. the probability that peter picks up 2 bruised apples is:
b. the probability that peter picks up a bruised apple first but a good one on his second attempt is:

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?