There's a baseball team that consists of 20 kids. At the end of the season, they all go to the coach's house to have a barbecue. The coach says, "You can't wear your hats at the barbecue." So, all the kids take their hats and throw them in a big pile. They fill their little faces with hot dogs and corn on the cob. At the conclusion of the evening, they all reach in at random, grab a hat and put it on their heads.<p>What's the probability that 19 out of 20 of these kids get their correct hat?
If 19 get their hat, won't the 20th also? There won't be another hat to get mixed up with...
So... 1/(20!) ?
It's been awhile since I've mathed. Could be way off. Is this your homework?