Answer:
18% that the athlete is disqualified but is actually clean
Step-by-step explanation:
In order to find the probability of two events happening together, in this case the athlete being disqualified and being clean, we need to multiply the probabilities. So,
It is a 90% chance that the athlete is clean and a 2% chance that the test fails so multiply the two
.9 * .2 = .18
This means that it is an 18% chance that the athlete is clean but is still disqualified.