Can anyone assist on rules for adding, subtracting, multiplying, and dividing proper and improper fractions. any is greatly

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?

An 18% discount on a watch saved a shopper $72. find the price of the watch before the discount

Solve the system of equations using the linear combination method. {4x−3y=127x−3y=3 enter your answers in the boxes.