A bag of marbles contains only blue and white marbles. The number of white marbles is six times the number of blue marbles. The bag contains 154 marbles. Write a system of
equations to determine how many of each color of marble is in the bag and then solve the
system of equations. Be sure to include let statements.

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?