A retailer$’$s demand for stock keeping unit $($SKU$)756-$RDU, white towels, is $20,000$ per year. The cost of placing an order is $$150,$ the cost per unit per year is $$40,$ and the holding cost is $5\%$ of product value a$.$  What is the economic order quantity?

b$.$ What will be the total logistics cost in this case?

c$.$ How many orders will the retailer place per year?

d$.$ The supplier sells these in cases of $500$ units only, such that any orders must be placed in multiples of $500$ units. This makes it impossible for the retailer to order the exact EOQ $($as calculated in part a$.).$ Given this constraint, what order quantity would you recommend and why?