Material facts: A and B have entered into a contract for the sale of goods.  Their agreement does not specify when delivery and payment should take place.  The seller wants payment at the same time as delivery.  The buyer wants to make payment some time after delivery takes place. 

The issue: In a contract for the purchase and sale of goods, when is payment due in relation to delivery?

The law provides that, unless otherwise agreed, the delivery of goods bought and sold and payment for those goods should take place at the same time.  (Note that stating and explaining the relevant law usually requires much more detail than in this example).

Conclusions.  In the present case, since the parties have not agreed otherwise, payment for the coffee beans is due at the time when A takes delivery.  A must therefore pay for the coffee beans when taking delivery, and not at a later time.

This outcome seems reasonable since otherwise the seller, who has not dealt with the buyer before, runs the risk of not being paid after parting with the goods.