Answer:
There are a total of 4 + r + 6 marbles in the bag
The probability of a blue is [tex]\frac{4}{10+r}[/tex]
The probability of 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]
Step-by-step explanation:
