What is the difference in length between a 1 1/4 inch button and a 3/8 inch button

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?

Sara made $253 for 11 hours of work. at the same rate how much would he make for 7 hours of work?

What is the scale factor of two similar pyramids with volumes of 64 cubic feet and 8 cubic feet