HW 5 Question #3
Help: Guessing on an exam
In a multiple choice exam, there are 5 questions and 3 choices for each question. Nancy has not studied for the exam at all and decides to randomly guess the answers. What is the probability that:
(a) the first question she gets right is the problem 1? and (c)she gets at least one question right?
I am not sure how to look at problem (a). correct on the first problem would be (1/4). Part (c) should be 1-(3/4)^5. I don't know what I am doing wrong.
Thanks, Beau
Comments
If there are 3 choices for each question, then the probability that she gets one correct is 1/3 and the probability that she get's one wrong is 2/3. I'm not sure where you're getting your 1/4 and the 3/4 from? It might be that you hit the retry button and got different numbers.
Assuming four choices, then I agree with your answers. Assuming 3 choices, then I don't agree with your answers.
Hallucinations