Consider a basic economic order quantity $($EOQ$)$ model with the

following characteristics:

Item cost: $$15$

Item selling price: $$20$

Monthly demand: $500$ units $($constant$)$

Annual holding cost: $$1\mathrm{.}35$ per unit

Cost per order: $$18$

Order lead time: $5$ working days

Firm's work year: $300$ days $(50$ weeks @ $6$ days per week$)$

Safety stock: $15\%$ of monthly demand

For this problem, determine the values of: