Respuesta :
Given:
Total number of marbles = 15
Probability of randomly selecting a green marble = [tex]\dfrac{1}{5}[/tex].
Probability of randomly selecting a green marble, replacing it, and then randomly selecting a blue marble = [tex]\dfrac{2}{25}[/tex].
To find:
The number of blue marbles.
Solution:
Let the number of blue marbles be x.
[tex]\text{Probability}=\dfrac{\text{Favorable outcomes}}{\text{Total outcomes}}[/tex]
[tex]P(Blue)=\dfrac{x}{15}[/tex]
It is given that,
[tex]P(Green)=\dfrac{1}{5}[/tex]
Probability of randomly selecting a green marble, replacing it, and then randomly selecting a blue marble is [tex]\dfrac{2}{25}[/tex]. So,
[tex]P(Green)\times P(Blue)=\dfrac{2}{25}[/tex]
[tex]\dfrac{1}{5}\times \dfrac{x}{15}=\dfrac{2}{25}[/tex]
[tex]\dfrac{x}{75}=\dfrac{2}{25}[/tex]
Multiply both sides by 75.
[tex]\dfrac{x}{75}\times 75=\dfrac{2}{25}\times 75[/tex]
[tex]x=2\times 3[/tex]
[tex]x=6[/tex]
Therefore, the number of blue marbles in the bag is 6.
