Cheeseburger and Taco Company purchases 14,515 boxes of cheese each year. It costs $29 to place and ship each order and $6.68 per year for each box held as inventory. The company is using Economic Order Quantity model in placing the orders.
hardly a problem for you ( coz I can do it so it must be simple )
there seem to be quite a few functions f = a/Q + bQ
in economics
and they all have a minimum df/dQ , at Qmin = root ( b/a)
so I have learnt something .....
also for production and I read money supply
( learn once and use three times )