##### probability problem with money

label Statistics
account_circle Unassigned
schedule 1 Day
account_balance_wallet \$5

A container holds 15 quarters and 9 dimes.  Two coins are drawn one at a time.

a.       Find the probability of getting 3 dimes, if the coins are drawn without replacement.

b.      Find the probability of getting 3 quarters, if the coins are drawn with replacement.

Jun 2nd, 2015

so there are 24 coins to begin with

then we have 15 quarters and 9 dimes

and we draw 2 coins at a time

as im sure you can tell we have repetition and since it does not seem orders matter we can use combinations. so doing n+1-1Cr (n=24(total items) and r= how many are being taken) we get 2600 repetitions

now there is only 1 in which all 3 dimes can be picked since it does not matter if dime #1-3 is picked or dime #4-6 is picked it is still counted as one. so the probability is 1/2600.

now for the second one it is similar to the first in which this case they are replaced so the probability of drawing a coin does not change since we replace them after each one. which means the probaiblity is 15/24^3=.244. This is because it does not change the probability as we pick the coins up

Jun 2nd, 2015

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Jun 2nd, 2015
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Jun 2nd, 2015
Oct 20th, 2017
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