Problem ? 42. How many galions should be ordered each time to minimize total anmual variable costs? (5how all calculations.) item cost per gallon = 55 Yariable costs of stocing it in inventory amount to 25% of unit cost pec year. Paperwork and shipping costs for placing an order are 510 per ordef. Average usage =500 eallons at 49.44 b- 92.11 c- 42.55 d. 100.001 e- None of the above