An urn contains nine blue balls and seven yellow balls. If three balls are selected randomly without being​ replaced, what is the probability that of the balls​ selected, one of them will be blue and two of them will be​ yellow?

Respuesta :

Answer:

[tex]Probability = \frac{27}{80}[/tex]

Step-by-step explanation:

Given

[tex]Blue =9[/tex]

[tex]Yellow = 7[/tex]

Required

Determine the probability that one of the balls is blue while others is yellow

The order of selection may be any of these three:

Yellow, Yellow, Blue or Yellow, Blue, Yellow or Blue, Yellow, Yellow

Solving Yellow, Yellow, Blue

[tex]Probability = P(Y_1) * P(Y_2) * P(B)[/tex]

[tex]Probability = \frac{7}{16} * \frac{6}{15} * \frac{9}{14}[/tex]

[tex]Probability = \frac{1}{8} * \frac{1}{5} * \frac{9}{2}[/tex]

[tex]Probability = \frac{9}{80}[/tex]

Solving Yellow, Blue, Yellow

[tex]Probability = P(Y_1) * P(B) * P(Y_2)[/tex]

[tex]Probability = \frac{7}{16} * \frac{9}{15} * \frac{6}{14}[/tex]

[tex]Probability = \frac{9}{80}[/tex]

Solving Blue, Yellow, Yellow

[tex]Probability = P(B) *P(Y_1) * P(Y_2)[/tex]

[tex]Probability = \frac{9}{16} * \frac{7}{15} * \frac{6}{14}[/tex]

[tex]Probability = \frac{9}{80}[/tex]

Hence:

The required probability is:

[tex]Probability = \frac{9}{80} + \frac{9}{80} + \frac{9}{80}[/tex]

[tex]Probability = \frac{27}{80}[/tex]