Expected Value Question

Question

If a test has 30 questions each with 4 answers what would be the expected value if you guessed all 30 questions. The test is out of 100 points.

Answer 1

Hello Garrett, thank you for posting your question!

When you’re dealing with expected value you want to start by finding the probability of a successful guess.

Since there are 4 answers for each question the odds would be ¼ = 0.25.

From there you can multiply the number of questions by those odds

30 * 0.25 = 7.5

The last step then is to scale that to a value out of 100

(7.5/30) * 100 = 25.

So the expected score on the exam would be a 25 if you guessed on each question.

I hope that helps :)