Multinomial distribution

A multinomial distribution is like a special kind of lottery. It's used to figure out the chances of different outcomes happening. Say you have a bag with 20 balls in it: 5 red balls, 7 yellow balls, and 8 green balls. If you draw one ball at random from the bag, we can use a multinomial distribution to figure out the chances of it being red, yellow, or green. We could say that the chance of drawing a red ball is 5 out of 20, or 5/20 or 25%. The same goes for a yellow ball (7/20 = 35%), and a green ball (8/20 = 40%). In the end, you get 100%, because there are all 20 balls in the bag and you can't draw more than one!