4. The state's Department of Administrative Services maintains a few light planes for official use. $10,000 has been allocated for fuels, which are purchased on a competitive hid basis. By adjusting the planes' engines, varying proportions of regular, super, and fuel additive can be used. The department wants to determine how many gallons of each type to purchase from each of the only two bidders, Poly Oil Co. and Petros Corp. The bids' summary follows: Price per gallon Maximum to be supplied (gallons) Poly Petros Poly Petros Regular Gh