Shaniqua is taking a multiple choice exam and is going to guess all of her answers. There are 10 questions on the exam, each question with 3 possible choices and only one correct choice. What is the probability that she will make at least 60% on the exam just by guessing?
Here is as far as I have gotten:
there are 3^10 = 59049 possible ways to fill out the exam answer sheet. I know that I need to add the probabilities of getting 6/10 correct + prob7/10 + prob8/10 + prob9/10 + prob10/10
i know that the probability of getting 10/10 by guessing is 1/59049, but I dont understand how to compute the probability of the others, can someone please point me in the right direction