$12\mathrm{.}20$ Bell Computers purchases integrated chips at $$350$ per

chip. The holding cost is $$35$ per unit per year, the ordering cost is

$$120$ per order, and sales are steady, at $400$ per month. The company$$s supplier, Rich Blue Chip Manufacturing, Inc., decides to offer

price concessions in order to attract larger orders. The price structure is shown below.

Rich Blue Chip$$s Price Structure

Quantity Purchased Price$/$Unit

$199$ units $$350$

$100199$ units $$325$

$200$ or more units $$300$

a$)$ What is the optimal order quantity and the minimum cost for

Bell Computers to order, purchase, and hold these integrated

chips?

b$)$ Bell Computers wishes to use a $10\%$ holding cost rather than

the fixed $$35$ holding cost in part $($a$).$ What is the optimal order

quantity, and what is the optimal cost? PX