An urn contains 5 blue marbles and 4 yellow 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 blue? yellow​?
​(b) What is the probability that exactly one marble is blue​?

Respuesta :

Answer:

(a)The probability that both marbles are blue=5/18

The probability that both marbles are yellow=1/6

(b)The probability that exactly one marble is blue​=5/9

Step-by-step explanation:

Blue marbles=5

Yellow marbles=4

Total marbles=5+4=9

(a)

Probability of drawing first  blue marble=5/9

Probability of drawing second blue marble without replacement=4/8

The probability that both marbles are blue

[tex]=\frac{5}{9}\times \frac{4}{8}=\frac{5}{18}[/tex]

Probability of drawing first  yellow marble=4/9

Probability of drawing second yellow marble without replacement=3/8

The probability that both marbles are yellow

[tex]=\frac{4}{9}\times \frac{3}{8}=\frac{1}{6}[/tex]

(b)

The probability that exactly one marble is blue​

=Probability of first blue marble (Probability of second yellow marble)+Probability of first yellow marble (Probability of second blue marble)

The probability that exactly one marble is blue​

=[tex]\frac{5}{9}\times \frac{4}{8}+\frac{4}{9}\times \frac{5}{8}[/tex]

=[tex]\frac{5}{18}+\frac{5}{18}[/tex]

=[tex]\frac{10}{18}=\frac{5}{9}[/tex]