Which of the following is not a reason that private firms do not provide public goods?
a. the free-rider problem
b. public goods are unprofitable
c. the price system doesn't assign the cost of public goods to all
consumers
d. the government refuses to grant subsidies to firms who provide public
goods

An allergy products superstore buys 6000 of their most popular model of air filters each year. the price of the air filters is $18. the cost of ordering and receiving shipments is $12 per order. accounting estimates annual carrying costs are 20% of the price. the supplier lead time is 2 days. the store operates 240 days per year. each order is received from the supplier in a single delivery. there are no quantity discounts. what is the store’s minimum total annual cost of placing orders & carrying inventory?