SOLUTION: A pizza pub is open 7 days a week. The manager allows each of the three employees to select one day off a week. That is the probability all 3 select the same day given that all 3 s

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Question 240348: A pizza pub is open 7 days a week. The manager allows each of the three employees to select one day off a week. That is the probability all 3 select the same day given that all 3 select a day beginning with the same letter.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A pizza pub is open 7 days a week. The manager allows each of the three employees to select one day off a week. What is the probability all 3 select the same day given that all 3 select a day beginning with the same letter.
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The only days beginning with the same letter are saturdaya and sunday.
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P(all select the same | all select saturday or sunday)
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P(all select saturday or sunday) = 2(1/2)^2 = 1/2
P(all select the same AND all select saturday or sunday) = (2/7)^2
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P(all select same | all select sat or sun) = (2/7)^2/(1/2) = 8/49
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Cheers,
Stan H.