00:01
Okay, so this question is about getting three of a kind from a deck of cards.
00:09
Now, there's some information missing.
00:12
It doesn't say how many cards are dealt.
00:15
So i'm just going to go with a standard hand of five, but know that if your question is a little different, all you have to do is change the number from five to four or six or whatever.
00:27
Anyway, to do this, we're going to use these.
00:30
These are called binomial coefficients.
00:33
And these are the way you calculate poker hands.
00:36
And this is the symbol.
00:38
You pronounce it in choose k.
00:41
It's n factorial divided by k factorial times n minus k factorial.
00:48
You don't know what a factorial is.
00:53
The easiest way to show you would be an example, 5 factorial would be 5 times 4 times 3, times 2 times 1.
01:02
So it's just that number multiplied by all the integers down to one.
01:09
Anyway, this is how many ways can cards be selected from a 52 card deck? well, again, i'm just going to choose a hand of five cards here.
01:23
That's going to be 52 choose five, which i'll write this one out...