Asteel plant has two sources of ore, source a and source b. in order to keep the plant running, at least three tons of ore must be processed each day. ore from source a costs $20 per ton to process, and ore from source b costs $10 per ton to process. costs must be kept to no more than $80 per day. moreover, federal regulations require that the amount of ore from source b cannot exceed twice the amount of ore from source a. if ore from source a yields 300 lbs of steel per ton, and ore from source b yields 400 lbs of steel per ton, how many tons of ore from each source should be processed each day to maximize the amount of steel produced?
a) 1 ton from source a, 2 tons from source b
b) 2 tons from source a, 4 tons from source b
c) 3 tons from source a, 0 tons from source b
d) 4 tons from source a, 0 tons from source b