John owns a hardware store. He has at most $1,000 to spend on restocking his pipes. Steel pipes cost $100, and plastic pipes cost $50. He needs at least 5 steel pipes and no more than 10 plastic pipes. Identify the graph that shows all possible combinations of steel and plastic pipes that he can buy. Also identify two possible combinations.

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?