Just owns a coffee shop. She experimented with mixing city roast Colombian coffee that costs $7.80 per pound with French roast Columbian coffee that costs $8.10 per pound to make a 20 pound blend. Her blend should cost her $7.92 per pound. How much of each type of coffee should she buy?

In a test for esp (extrasensory perception), a subject is told that cards only the experimenter can see contain either a star, a circle, a wave, or a square. as the experimenter looks at each of 20 cards in turn, the subject names the shape on the card. a subject who is just guessing has probability 0.25 of guessing correctly on each card. a. the count of correct guesses in 20 cards has a binomial distribution. what are n and p? b. what is the mean number of correct guesses in 20 cards for subjects who are just guessing? c. what is the probability of exactly 5 correct guesses in 20 cards if a subject is just guessing?