Which expressions are equivalent to x + x + x + 2x Choose 2 answers:

(Choice A)
3x + 23x

(Choice B)
3 + 2x

(Choice C)
3(x+2)

(Choice D)
2(x + 1) + x

(Choice E)
5x

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?