Suppose I pick (without looking) a jelly bean from a box containing four red beans and seven blue beans. I record the color and put the bean back in the box. Then I choose a bean again. What is the probability of getting a blue bean both times? (Enter your probability as a fraction.)

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emmaleannp emmaleannp · Answer 1 · 2019-10-01T02:45:42+02:00

Answer: 7/11

Step-by-step explanation:

If you pick a blue bean once then put it back. the total amount of blue beans, and beans in total, stay the same.

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MrRoyal MrRoyal · Answer 2 · 2021-10-01T17:48:41+02:00

Probabilities are used to determine the chances of an event.

The probability of selecting blue balls both times is [tex]\frac {49}{121}[/tex]

The given parameters are:

[tex]Red = 4[/tex]

[tex]Blue = 7[/tex]

[tex]Total=11[/tex]

The probability of selecting blue the first time is:

[tex]P(Blue) = \frac{Blue}{Total}[/tex]

[tex]P(Blue) = \frac{7}{11}[/tex]

When the selected ball is returned,

The probability of selecting another blue is:

[tex]P(Blue) = \frac{Blue}{Total}[/tex]

[tex]P(Blue) = \frac{7}{11}[/tex]

So, the probability of selecting blue, both times is:

[tex]Pr = P(Blue) \times P(Blue)[/tex]

[tex]Pr = \frac 7{11} \times \frac 7{11}[/tex]

[tex]Pr = \frac {49}{121}[/tex]

Hence, the probability of selecting blue balls both times is [tex]\frac {49}{121}[/tex]