Acme Mfg., Inc. creates 3 types of lawn tractor in one of its several plants, Mitymite, All-purpose and Powerhouse. In terms of labor used, Mitymite needs three hours for parts acquisition, two hours for assembly and one hour for packaging and shipping. All-purpose needs four hours for parts acquisition, three hours for assembly and two hours for packaging and shipping. At last, Powerhouse needs 4 hours for parts acquisition, 6 hours for assembly and two hours for packaging and shipping. If Acme available the total of 520 hours of labor for parts acquisition, 440 hours for assembly and 240 hours for packaging and shippping and management wishes all of the hours in each category of labor utilized in that category in production of the very popular tractors, how many Mitymites must be made so no unused time is left over?