A surprise quiz was given yesterday in your biology class with 8 multiple choice questions.A classmate who took it claimed to have guessed on every question,but got them all correct.Each question had 5 possible answers.Should you believe him? Explain,basing your argument on a simulation involving at least 10 runs.
A)No,the possibility of that happening is very small,about 1.51571657.
B)Yes,it is likely.
C)It is hard to tell.The simulation would need to have more than 10 runs.
D)No,the possibility of that happening is very small,about 0.00000256.
E)Yes,it is possible.

Question

Quizplus · Accepted Answer

The probability of getting all 8 questions correct by guessing on each one is (1/5)^8 = 0.00000256 or about 0.0003%. This is a very small probability, and therefore it is unlikely that the classmate actually guessed on every question and got them all correct. To further confirm this, we could run a simulation with more than 10 runs, but based on the probability calculation alone, it seems that we should not believe the classmate.

A Surprise Quiz Was Given Yesterday in Your Biology Class