SOLUTION: A teacher has 20 students in her class. She randomly will select 4 students for a project. a)Find the probability that a specific group of 4 students is selected b)Mary is not

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Question 453941: A teacher has 20 students in her class. She randomly will select 4 students for a project.
a)Find the probability that a specific group of 4 students is selected
b)Mary is not to be in the selected group. Find the probability that Mary is in the selected group
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A teacher has 20 students in her class. She randomly will select 4 students for a project.
a)Find the probability that a specific group of 4 students is selected
# of ways to get the "specific group: 1
# of ways to select a random group of 4: 20C4
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P(get specific grp of four) = 1/20C4 = 1/4845
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b)Mary is not to be in the selected group. Find the probability that Mary is in the selected group
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Ans: zero
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Cheers,
Stan H.
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