Algebra
posted by Doris .
A manager has $1170 made up of twenties and fifties. The total is 36 bills. How many fiftydollar bills does the manager have?

Please show me how to set this problem up. I am confused.

You need to set up a system of equations. No one knows how many of each type of bill there is. Let t=twenties and f=fifties.
t+f=36
20t+50f=1170
20(t+f=36)=20t+20f=720
20t+50f=1170
30f=450 f=15
t+15=36
15 15
t=21