00:01
So recall that this is in items choose r.
00:03
This is choosing n items, choosing r items from n, from n possibilities.
00:20
And this means that order does not matter.
00:22
If order did matter, then i would do a permutation step.
00:27
Okay.
00:28
So let's say i want to choose six numbers from 59 numbers.
00:32
This is saying i could select one, two, three, and that's same as selecting 3, 2, and 1.
00:38
It doesn't matter how it was selected, but the orders are selected.
00:41
So this is 59, choose 6 different numbers for the lottery.
00:45
This formula would be the first number factorial over the bottom number factorial, over subtract these two numbers factorial...