Why is it important to convert rates to the same units before comparing them

Can someone me i’m confused. will give brainliest and a whole bunch of points

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?

*segment an is an altitude of right ? abc with a right angle at a. if ab = 2root 5 in and nc = 1 in, find bn, an, ac.