SOLUTION: In a history class, Colin and Diana both write a multiple choice quiz. There are 10 questions. Each question has 5 possible answers. What is the probability that Diana will pass th
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Question 1002984: In a history class, Colin and Diana both write a multiple choice quiz. There are 10 questions. Each question has 5 possible answers. What is the probability that Diana will pass the test if she studies so that she has 75% chance of answering each question correctly. Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! I don't know what passing is. I will assume 70%.
The 5 possible answers appears not to be relevant, since she has a 75% chance of answering each question correctly.
She has to get 7 or more correct.
10C7(0.75)^7(0.25)^3=0.2503
10C8(0.75)^8(0.25)^2=0.2816
10C9(0.75)^9(0.25)=0.1877
0.75^10=0.0563
P=0.7759
