Leilani$$ Lavender's law office has traditionally ordered ink refills $60$ units at a time. The firm estimates that carrying cost is $40\%$ of the $$$$10\mathrm{.}00$ unit cost and that annual demand is about $240$ units per year. The assumptions of the basic EOQ model are thought to apply.

$$a$)$ For what value of ordering cost would its action be$$ optimal?

$$

enter your response here per order $($round your response to two decimal$$ places$).$