Question 201767: jan would like to hang 19 of her favorite photo's on a wall in her room, but she has room for only 9. One of the photo is a picture of her grandma. If Jan makes her selection at random, what are the probability that she will pick the picture of her grandma?
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! jan would like to hang 19 of her favorite photo's on a wall in her room, but she has room for only 9. One of the photo is a picture of her grandma. If Jan makes her selection at random, what are the probability that she will pick the picture of her grandma?
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Find the number of sets of 9 photos that DO NOT have grandma's photo
in the set. : 18C9 = 48620
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Find the total number sets of 9 photos. : 19C9 = 92378
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So the number of sets of size 9 that DO HAVE grandma's photo
is 92378-48620 = 43758
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So the probability she will pick grandma's photo is 43758/92378 = 0.4737..
Cheers,
Stan H.
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