Question 768256: A fund-raising raffle has sold 100 tickets which are numbered 1 to 100, one ticket is chosen, find the probability that the ticket:
Won't be 57.
Will have a 5 as its last digit.
Won't end in zero.
These are complementary events questions.
Thanks
Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A fund-raising raffle has sold 100 tickets which are numbered 1 to 100, one ticket is chosen,
Find the probability that the ticket:
Won't be 57:::::: 1-P(# is 57) = 1-(1/100) = 0.99
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Will have a 5 as its last digit.
Ways that can happen::: 5,15,25,35,45,55,65,75,85,95---- 10 ways
P(5 is the last digit) = 10/100 = 0.10
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Won't end in zero.
Ways it can end in zero::: 10,20,...90,100-------10 ways
P(won't end in zero) = 1 - 0.1 = 0.90
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Cheers,
Stan H.
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