Asked by Bob
An urn contains 55 green marbles and 44 red marbles. One marble is removed, its color noted, and not replaced. A second marble is removed and its color is noted.
(a) What is the probability that both marbles are green? red?
(b) What is the probability that exactly one marble is green?
(a) What is the probability that both marbles are green? red?
(b) What is the probability that exactly one marble is green?
Answers
Damon
99 marbles
first green = 55/99
second green = 54/98
so
(55/99)(54/98)
etc
for b
first green, second red plus first red, second green
first green = 55/99
second green = 54/98
so
(55/99)(54/98)
etc
for b
first green, second red plus first red, second green