A farmer has 100 acres on which to plant oats or corn. Each acre of oats requires $18 capital and 2 hours of labor. Each acre of corn requires $36 capital and 6 hours of labor. The farmer has $2100 available for capital and 360 hours for labor. If the revenue is $55 from each acre of oats and $125 from each acre of corn, what planting combination will produce the greatest revenue?

I have to find the combination of corn and oats that gives the greatest revenue, so I think my variables should stand for acres of corn C and acres of oats O. C + O < 100, and C > 0 and O > 0.

The "capital" part gives me 18O + 36C < 2100 and the "labor" part gives me 2O + 6C < 360.

The revenue formula is F = 55O + 125C.

For my graph, I did O on the x axis and C on the y axis. When I graphed the lines, it looked like the line C = 60 - O/3 didn't actually make one of the sides of the shaded part. Did I do this wrong?