00:01
So we have six narcotic pills and we have nine vitamins.
00:05
So a total of 15 pills are being chosen, are being put into a vial.
00:10
And we know that they are selecting three, or that's the supposition that they're selecting a sample of three.
00:17
And we want to know what's the probability of getting of those three at least one narcotic pill.
00:28
And so that is going to be the complement of the probability of getting none, zero pills, narcotic pills.
00:39
And so we know that the denominator for this setting would be that there are 15 pills and we're getting groups of three.
00:49
And this comes out to be a denominator of 455 ways to do that.
00:56
And we want the numerator to be zero narcotics, which means you pull out three vitamins.
01:04
And the number of vitamins is nine, and you want groups of three.
01:09
And so let me go back and find what that nine choose three is.
01:12
We could do it longhand two.
01:14
But let's just use a calculator...