00:01
We want to find the expected value of betting on a red for different bets.
00:05
So let's first of all see what the probability of getting a red is.
00:09
So we have there's 18 red slots on that roulette.
00:12
So 18 out of 38 or 9 out of 19 is the probability of getting a red.
00:19
So the probability of a red is going to be 9 out of 19.
00:23
The probability of not getting a red then is going to be 10 out of 19.
00:30
So what is going to be our expected value? well, we're going to bet on red.
00:35
So that means that we're going to be spending that $1.
00:38
And when we win, we're going to win that $1.
00:43
We're going to get our dollar back, plus we're going to get another dollar.
00:47
So that means that 9 .19th of the time, we're going to win an extra dollar.
00:56
We're going to get $2 back, but we're going to have to bet a dollar.
01:01
And then the other 1019th of the time, oops, i didn't mean to put that, the other 1019th of the time, we're going to lose our dollar.
01:12
So that means we simply add our probabilities together, and then we're going to get our answer.
01:18
We'll go to the calculator in a minute, and we'll get all those.
01:21
For $5 and $10, the only thing that's going to change is going to be the values in the parentheses.
01:27
So 9 .19th at the time, when we win, we'll get $10...