There are a total of 20 bills in the wallet, so the probability of selecting a $1 bill first is 7/20. Since we do not replace the selected bill, there are now 19 bills in the wallet, of which 5 are $10 bills. Therefore, the probability of selecting a $10 bill second, given that a $1 bill was selected first, is 5/19.
To find the probability of selecting a $1 bill first and then a $10 bill, we multiply the probabilities:
P($1, then $10) = (7/20) x (5/19)
P($1, then $10) = 35/380
P($1, then $10) = 0.0921
Therefore, the probability of selecting a $1 bill first and then a $10 bill is approximately 0.0921 or 9.21%.
You have seven $1 bills, three $5 bills, five $10 bills, and five $20 bills in your wallet. You select a bill at random. Without replacing the bill, you choose a second bill. What is P($1, then $10)?
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