Yeah, that's it (apart from writing the 0.8 fraction upside-down of course! and you didn't express the final answer to two decimal places)
Hey, I don't know where to start with this question.
Question:
On a multiple-choice test of 10 questions, each question has 5 possible answers. A student is certain of the answers to 4 questions but is totally baffled by 6 questions. If the student randomly guesses the answers to those 6 questions, what is the probability that the student will get a score of 5 or more on the test? Express your answer correct to two decimal places.
Solution
Okay, so I am assuming that the 4 questions the student is certain about are guaranteed to be correct. That leaves the other 6. All I really need to find here is the probability of getting all 6 questions incorrect. So I believe that would be:
which gives me: .
So to find the probability that the student will get a score of 5 or more on the test is which gives an answer of: (my calculator for some reason put it into decimal form -.-).
Did I do this question correctly? I actually originally had very little on this question at all, and as I was writing this out this solution came to me. Does this solution make sense?
- Thanks!