00:01
In the study of probability, we often talk about odds.
00:04
Odds are a little different from probability because odds are a comparison of what you are looking for compared to what isn't what you're looking for, where probability is what i'm looking for compared to the total number of items or objects or outcomes.
00:24
So when i'm rolling a dye, there are six sides to a die.
00:29
What are the odds in favor of getting a two? well, i need to ask myself how many twos are on a die? there's one.
00:38
Compared to how many sides on a die are not two, and that would be five.
00:45
And the odds against, we just switch it around.
00:48
There are five sides to a dye that are not two, and there's one that is.
00:55
So rolling a die, what are the odds that it'll be even? this is kind of an interesting one.
01:00
There are three evens, two, four, and six, and there are three that are not even.
01:06
So our odds are 3 to 3, or we can reduce that 1 to 1, or we can just say 1.
01:13
And the against is the same.
01:15
There are 3 that are not even.
01:17
There are 3 that are even.
01:19
And again, we could say that that has the odds of 1.
01:24
We could also say it up here that this has an odds of 5.
01:27
So we could say it that way, or 5 to 1.
01:30
How about in a standard deck of cards? what are the odds that it's a spade? so again, there are 13 spades.
01:38
And there are 39 cards that are not a spade.
01:42
And we can reduce this one, two, three, meaning there's one suit that are spades, there are three suits that are not...