SOLUTION: A test is given with 10 T-F questions. How many different ways can the answer sheet be filled out so that 8 or more questions are answered correctly? I am drawing a blank and do no

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Question 433457: A test is given with 10 T-F questions. How many different ways can the answer sheet be filled out so that 8 or more questions are answered correctly? I am drawing a blank and do not know where to start?
Bob
Found 2 solutions by jorel1380, stanbon:
Answer by jorel1380(3719) (Show Source):
You can put this solution on YOUR website!
If you have 10 questions, of which 8 are solved correctly, then you have 10C8 different combinations of answers:
10C8=10x9x8!/2x1x8!=5x9=45 different combinations.

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
A test is given with 10 T-F questions. How many different ways can the answer sheet be filled out so that 8 or more questions are answered correctly? I am drawing a blank and do not know where to start?
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Binomial Problem with n = 8 and p = 1/2
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P(8<= x <=10) = 1-P(0<= x <=7)
= 1 - binomcdf(8,0.5,7)
= 0.0039
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Cheers,
Stan H.