The event of selecting the first straw affects the probability of selecting the second straw. This is because there is one fewer straw we can pick. Therefore, the events are dependent.
Probability of Dependent Events
If two events A and B are dependent, then the probability that A and B will occur is
P(AandB)=P(A)* P(B|A)
Here, we know that Milo picks a straw first and keeps the shortest straw. This means that there are 3 more straws we can pick and 1 of them is the longest. If Frank picks second, then the probability that he picks the longest straw is 1 3. This corresponds with answer C.
