Answer
a)0.474
b)10:9
c)18\$
d)20$
Work Step by Step
a)We have 38 different outcomes, out of which 18 are good. We know that $probability=\frac{number \ of \ good \ outcomes}{number\ of\ all\ outcomes}$, hence $probability=\frac{18}{38}=0.474.$
b) We know that $odds=\frac{number \ of \ good \ outcomes}{number\ of\ all\ outcomes-number \ of \ good \ outcomes}$, hence $odds=\frac{38-18}{38-(38-18)}=\frac{20}{18}$, hence the odds are 10:9.
c) If the payoff odds are 1:1 it means that we double our money if we win, hence we will win another 18\$.
d) If the payoff odds were 10:9, we would win $\frac{10}{9}\cdot18=20 \$$
