Systems of equations word problem A small rental-car company has a total of 120 cars consisting of 3 types: economy, mid-size, and full-size. The daily rental fee for each is: $22 for economy, $26 for mid-size, and $31 for full-size. If there are 15 more mid-size than economy and, on a certain day, a total of $3085 is collected when all the cars are leased out, how many of each type of car does the company own?