7. The Malibu Company uses 800,000 tons of stone per year. The carrying costs are $400/ton. The cost per order is $1000.. (Assume a linear usage rate and that HRBC runs its inventory down close to zero as the replenishment order arrives.)

a. Calculate the economic order quantity per order.

b. Calculate the optimal number of orders per year.

c. Calculate the optimal annual order costs.

d. Calculate the optimal carrying costs.

e. Calculate the total costs of optimal inventory.