Demand for a product is 25 tones / day and there are 200 working days / year. ==> D =

25(200) = 5000.
Ordering cost is €48 / order ==> S = 48
Carrying cost is €2 / unit / year ==> H = 2
Price schedule is as follows:
Quantity (Q) Price (P)
600-... 8
400-599 9
0-399 10
What is the best quantity that we could order to minimize our total annual cost?