A manager has just received a revised price schedule from a vendor. What ordeiquantity should the manager use in order to minimize total costs? Annual demand is $150$units, ordering cost is $l$2,$ and annual carrying cost is $l$\mathrm{.}5$ per unit.

Quantity

$1-59$

Unit Price

$$15$

$60-99$

$100$ or more

$$10$

a$.$ f$6$ Pts$]$ Determine the optimal order quantity and the total annual inventory cost.

b$.$ f$6$ Pts$|$ Determine the optimal order quantity and total annual inventory cost if thecarrying cost is $20\%$ of the unit price.