The area of a campground is 1,400 square meters. A tent requires 8 square meters and an RV requires 30 square meters of space. The capacity of the campground is 120 spots, including both tents and RVs. If the cost to camp in a tent is $3.00 and an RV is $9.00, how many RVs should be in the campground to maximize income?

Question

phi · Answer

the question is
 how many RVs should be in the campground to maximize income

First step:   pick a letter to stand for "# of RV's
and while you are at it, pick a letter for "# of tents"

can you do that ?