The time t required to drive a certain distance varies inversely with the speed r. if it takes 2 hours to drive the distance at 40 miles per hour, how long will it take to drive the same distance at 45 miles per hour? about 1.78 hours 80 hours 2.25 hours 900 hours

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?

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?

Compute the standard deviation of the following set of data to the nearest whole number. 10, 10, 15, 20, 25