Company A purchases cases of fertilizer for its lawn-care business from a supplier who charges $30 per order and $50 per case.
Each case consists of five bags of fertilizer. Company A needs 2000 bags of fertilizer a year. Company A's annual holding costs are 30%.
If Company A only has room to hold 25 cases of fertilizer, how many cases should Company A order each time to minimize the total holding and ordering cost?