A box contains four white, three red, and two black marbles. Three marbles are chosen at random.

a. What is the probability that all three are the same color?

b. What is the probability that all three are different colors?

2 answers

a. If the events are independent, the probability of both/all events occurring is determined by multiplying the probabilities of the individual events.

P(white) = 4/9 * 3/8 * 2/7 = ?

P(red) = 3/9 * 2/8 * 1/7 = ?

P(black) = 0, since there are only 2 blacks

Either-or probabilities are found by adding the individual probabilities.

Add the above probabilities.

b. 4/9 * 3/8 * 2/7 = ?
They are not independent