SAT Question 79201024: Probability And Conditional Probability answer and explanation with Desmos solution

Choice B is correct. The probability of an event occurring is the ratio of the number of favorable outcomes to the total number of possible outcomes. It's given that there are $45$ band members, which is the total number of possible outcomes. It's also given that there are $11$ band members who play saxophone. Therefore, the number of favorable outcomes is $11$. Thus, the probability of selecting a band member who plays saxophone is $\frac{11}{45}$.