A man discovered he had only $5 bills and $1 bills. The number of $1 bills was 4 more than 3 times the number of $5 bills. He had a total of $36. How many of each kind of bill did he have?
Let n be the number of $5 bills, then the number of $1 bills is 3n+4 with value $(3n+4). The value of the $5 bills is $5n. So the total value is 3n+4+5n=36, 8n=32, n=4. Therefore there are 4 $5 bills and 16 $1 bills.
