The diagram shows a cuboid.
ab = 10 cm
bc = 8 cm
5 cm
a string runs diagonally across the box
from b to hand is 25 cm long.
el
--
18 cm
10 cm
calculate the length ae.
give your answer correct to 3 significant figures.

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?