a.(2, -5, -3)
b.(-4, -1, -2)
c.(-2,3,5)
d.(2,5,3)
e.(4,1,2)

1. 2x - 4y + 3z = -7
2. x + 2y + z = 15
3. - 3.x + y + z= 2

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?