"Suppose that in a barter economy Tom bakes bread and Hans produces chocolates. Tom wants chocolates but Hans doesn't like bread, so Hans is unwilling to trade with Tom. Tom's problem is an example of which problem associated with a barter system?"

In a recent annual report, apple computer reported the following in one of its disclosure notes: "warranty expense: the company provides currently for the estimated cost for product warranties at the time the related revenue is recognized." this note exemplifies apple's use of: (a) conservatism.(b) matching. (c) realization principle. (d) economic entity.