There are four blue marbles, an unknown number of red (r marbles, and six yellow marbles in a bag. which expression represents the probability of randomly selecting a blue marble, replacing it, and then randomly selecting a red marble?
There are a total of [tex]4+r+6[/tex] marbles in the bag
The probability of choosing a blue is [tex] \frac{4}{10+r} [/tex]
The probability of choosing a red is [tex] \frac{r}{10+r} [/tex]
The probability of choosing a blue, replacing it, and then a red is [tex] \frac{4}{10+r} [/tex]×[tex] \frac{r}{10+r} [/tex] = [tex] \frac{4r}{100+20r+ r^{2} } [/tex]
