(part 4)

d. Follow the path on the tree. There are three ways to get a red marble on the first draw and eight ways to get a blue on the second draw. There are 3 × 8 = 24 ways to draw red then blue, so P(RB) = $\frac{24}{121}$.

Can you think of another way to find this probability? P(R on 1st draw AND B on 2nd draw) = P(RB) = $\left(\frac{3}{11}\right)\left(\frac{8}{11}\right)$ = $\frac{24}{121}$