When taking a 20 question test were each question has for possible answers it would be unusual to get blank or more questions correct by guessing alone how do I come up with an answer

Question

How do you come up with the answer? What say you were taking a 20 question multiple-choice test and each question has for possible answers. The question is it would be unusual to get ___ or more questions correct by guessing alone give your answer as a whole number

Answer 1

First of all you need to improve your English grammar so that you can write the question correctly. Then you need to use the binomial distribution with with p=.25 and n=20 to compute the answer to your question.