Question

you have some $5 dollar bills and $10 dollar bills in your wallet. You have a total of 12 bills that are worth $95 how many of each type do you have

Answer 1

This is very difficult and I cant believe It took me 6 minutes to do this so ok this is how I did it.

So we have unlimited $5 and $10 bills to use but we have to make it to $95 through only $12 bills so what I did was put like a pattern and wrote it down, I added the pic below so u can see what I did, hope it uploads but I put 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, 10, 5, and 10, so if we add it all the 10's up first It would be 10, 20, 30, 40, 50, 60, 70, OK so wait that's not the answer, its just a part, so keep 60 now add the rest of the 5's and now it would go like 5, 10, 15, 20, 25, so 25 + 70 = 95 which is true, so that would be it.

Answer: You have five, $5 dollar bills, and seven $10 bills.

Answer 2

let
x = # of $5 dollar bills
y = # of $10 dollar bills

x + y = 12 so x = 12 - y
5x + 10y = 95

substitute x = 12 - y into 5x + 10y = 95

5x + 10y = 95
5(12 - y) + 10y = 95
60 - 5y + 10y = 95
5y = 35
y = 7

x = 12 - 7 = 5

answer
# of $5 dollar bills = 5
# of $10 dollar bills = 7