This is one you would never tell at an airport.
A guy was at the ticket counter and was frightened that there may be a bomb on the plane. The counter person assured him that everything was really safe. But he was still frightened, so the counter person said that there would be a one in a million chance that there would be a bomb on the plane. The guy still would not resolve his fear, so the counter person said that having two bombs on a plane would have the chance of 2 million to one. The guy remained fearful, so the counter person said, "If you take your own bomb on the plane, you will then double the odds!"