00:01
This question is asking us to calculate the probability of getting a certain five card hand.
00:05
Specifically, we're trying to get three of a kind when you're just being dealt that five card hand from a standard 52 card deck.
00:13
And the four parts of this question are really just leading us through the big answer because this is a pretty complicated probability.
00:22
So looking at part a, we want to know how many ways can five cards be selected from a 52 card deck.
00:29
So for part a, i've got 52 total cards and i'm choosing a group of five.
00:36
I'm using a combination here because the order of these cards doesn't matter.
00:41
You're just getting a group of five cards when you're dealt that hand.
00:45
And so the combination, remember, uses the first, the big total is the first number.
00:51
So 52 cards in total.
00:53
And we are essentially counting groups of size five.
00:56
So that's where the five is coming from.
00:58
So this number comes out to be 2 ,598 ,960.
01:05
So that's how many total five card hands there are.
01:07
That's going to be the denominator of our eventual probability calculation.
01:14
Now, in part b, we have to be able to figure out how many ways you can get three of the same card selected from the deck.
01:22
So you want to imagine that you're kind of rifling through the deck of cards and you are picking your.
01:28
Group of three of one kind.
01:31
And so the way, that's how i like to think about it.
01:33
And so imagine, you know, first you have to decide, um, which, which kind do you want? which three of a kind? you want three aces.
01:40
Do you want three kings? do you want three fives? and the number of choices you have for that is 13 because there are 13 different kinds.
01:48
You can also phrase this as 13 choose one because of the 13 different kinds.
01:53
You're just picking initially one of them to be the, the three of a kinds that you're going to want.
01:59
So once i've, let's say, decided on queens, i want three queens.
02:03
Now i have to figure out, okay, how many groups of three queens can be chosen? because there are four total...