Element X decays radioactively with a half life of 6 minutes. If there are 900 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to
decay to 121 grams?
y = a(.5)^(t/h)

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?

How does reflecting or rotating a figure change the interior angles of the figure?

Find the solution(s) to x^2-14+49=0