00:01
So we have a multiple choice test.
00:02
There are only two choices for each question.
00:05
So the probability of getting it correct is 0 .5, if you guess.
00:10
There are four questions, so four trials, and we want the probability of no correct answers.
00:17
So this is a binomial distribution.
00:20
We have two outcomes, get it right or don't.
00:23
Same probability for each question, each question is independent.
00:27
And we want the probability of a binary.
00:30
None of them correct.
00:33
So there is a binomial formula.
00:35
We don't really need it here, but i will write it out.
00:39
Probability of exactly x successes is n choose x, p to the x, 1 minus p to the x.
00:47
So what this does is if i write out what's happening here, we have four wrong answers in a row...