Farina wrote:
chacinluis wrote:
Let the number of 5 dollar bills be 2x
Let the number of 1 dollar bills be 3x
So we get the ratio 2x/3x=2/3 as desired
We are looking for 3x
She paid for a $7 purchase using $5 dollar bills only, and used the least possible $5 bills.
So she used 2 $5 dollar bills.
The change was 10-7=$3
and she got it back in only $1 dollar bills.
So she gets 3 $1 dollar bills
After this transaction her number of
$5 dollar bills is 2x-2
$1 dollar bills is 3x+3
The ratio
(2x-2)/(3x+3) = 1/3
6x-6=3x+3
3x=9
Final Answer: 9
I didnt understand the highlighted part?
He used 2 of (his 3x) $5 dollar bills -->
2x - 2 and received back 3 $1 bills -->
3x + 3