4+1=5,5+2=12,6+3=21,8+11?​

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?

A6 ounce bottle of dressing costs $1.56 a 14 ounce bottle costs $3.36 a 20 ounce bottle costs $5.60 which has the lowest cost per ounce

What is the area of the shaded sector?