Examples of precommitments, to deal with people's time inconsistency problems, include the following except:

For each of the following pairs of products, state which are complements, which are substitutes, and which are unrelated

a. Digital camera and memory stick b. 7Up and Mountain Dew c. Swimsuits and flip-flops d. Tylenol and cat food e. Photocopier and paper

A perfectly competitive firm's profit per unit of output equals

a. price minus average variable cost b. price minus marginal cost c. total revenue minus total cost d. price times quantity e. price minus average total cost