This is a hypergeometric, geometric, negative binomial random variable, or Poisson.
A smuggler places 3 narcotic tablets in a bottle of 21 vitamin pills for a total of 24 pills. If U.S. customs tests 2 pills at random what is the probability that at least 1 narcotic pill will be found?
The professor gave the answer as 24%, I am just unclear on how to arrive at that.