Best Buy is concerned about its inventory of Sony Magnolia 85” 4K Ultra HD TVs. It wants to have at least 3,000 TVs available at a given time. It costs the firm $20 to place an order. It sells 50,000...

Best Buy is concerned about its inventory of Sony Magnolia 85” 4K Ultra HD TVs.  It wants to have at least 3,000 TVs available at a given time. It costs the firm $20 to place an order.  It sells 50,000 TVs a year and it costs $20 in storage/insurance per TV per year.

(a)  How many TVs should Best Buy order at a time?

(b  How many TVs does Best Buy have on average in stock?