Tom works the night shift at a gas station on the edge of Champaign. One night he mixed 3 stale doughnuts in with 13 fresh doughnuts.

Tom works the night shift at a gas station on the edge of Champaign. One night he mixed 3 stale doughnuts in with 13 fresh doughnuts. That night 6 customers bought one doughnut each, selecting them at random. What is the probability that at least 2 stale doughnuts were sold?