00:01
Okay, we are told the chance the person has the allergy is 0 .17, which means p of no allergy is 1 minus that, which will be 0 .83.
00:14
It's a binomial type problem.
00:16
You have success and failure.
00:18
Success here is being allergic, failure not allergic.
00:23
Now, what i want is exactly 17 to have the allergy.
00:26
So that means i want 0 .17 power of 6 .7.
00:30
Power of and then that means that i've got to have .83, it's 100 people.
00:39
So here must be 83 people to get 100 in total.
00:45
And that we can do more than one way.
00:49
A number of ways is the binomial number, which will be 117...