Given:
Total income form tips = $131
His tips consisted of $1 bills and $5 bills only.
Total number of bills = 47
To find:
The number of $5 bills.
Solution:
Let x be the number of $1 bills and y be the number of $5 bills.
Total bills : [tex]x+y=47[/tex] ...(i)
Total income : [tex]x+5y=131[/tex] ...(ii)
Subtract (ii) from (i), we get
[tex]x+5y-(x+y)=131-47[/tex]
[tex]x+5y-x-y=84[/tex]
[tex]4y=84[/tex]
[tex]y=21[/tex]
Therefore, the number of $5 bills is 21.
