A rug cleaning company sells three models. EZ model weighs 10 pounds, packed in a 10-cubic foot box. Mini model weighs 20 pounds, packed in an 8-cubic foot box. Hefty model weighs 60 pounds, packed in a 28-cubic foot box. A delivery van has 308 cubic feet of space and can hold a maximum of 440 pounds. To be fully loaded how many of each should it carry if the driver wants the maximum number of Hefty models?​