Leaky Pipe, a local retailer of plumbing supplies, faces demand for one of its SKUs at a

constant rate of $30,000$ units per year. It costs Leaky Pipe $$10$ to process an order to

replenish stock and $$1$ per unit per year to carry the item in stock. Stock is received four

working days after an order is placed. No backordering is allowed. Assume $300$ working

days a year.

a$)$ What is Leaky Pipe's optimal order quantity?

b$)$ What is the optimal number of orders per year?

c$)$ What is the total cost of ordering the optimal order quantity?

d$)$ What is the reorder point?