A farmer makes a feed mix from two different ingredients, A and B. Each
bag of ingredient A contributes 1 pound of required vitamins and 4 pounds
of required minerals to the feed mix. Each bag of ingredient B
contributes 2 pounds of the required vitamins and 2 pounds of the required
minerals to the feed mix. The feed mix must contain at least 40 pounds of
the required vitamins and 60 pounds of the required minerals. Because of
the additional nutrients in the ingredients, each batch of feed mix must
contain at least 5 bags of each ingredient. A bag of ingredient A costs
$8, and a bag of ingredient B costs $10. The farmer wants to know the
number of bags of each ingredient to use in the mix in order to minimize
total cost.