00:01
Okay, so we have this dog that has been bitten by four raccoons and is equal to four.
00:06
And each raccoon has a probability of holding rabies by, what is it, 10%, so 0 .1.
00:15
And then we want the probability that the dog has been bitten by at least one with rabies.
00:24
So we're going to say it's a success to have rabies when it's not.
00:27
And that's the same as saying the probability that r is greater than or equal to 1.
00:31
1, which we can also say this is going to be equal to the probability, or hold on a second, i'm wanting to say this a little bit differently.
00:40
This will be equal to the probability of 1 minus the probability that r equals 0, which is to say the dog did not get bin by any raccoons with rabies.
00:51
And what this is going to be is 1 minus 4 to 0.
00:57
So we'll have 4 factorial over 0 factorial 4 factorial, which this will just be 1...