=+A chain store offers to buy on contract a quantity of Twisteze that may average 4000 drums per month at f1.75 per drum. The chain store would re-seIl the drums under their own brand name: costs of colouring and substitute labeIling of the drums are insignificant and may be ignored. Sales to the chain store would give rise to no Exercises 381 sales commission or delivery costs (the customer would collect in his own transport).