Charles is training for a triathlon, a timed race that combines swimming, biking, and running. consider the following sentence: because his pool sessions are him swim more quickly, charles plans to reduce by 1 hour per week the time he spends training on the bike and increase by 1 hour the time he spends in the swimming pool; however, his wife says that he should stop doing any biking and running and spend all 20 hours per week in the pool. which basic principle of individual choice does charles's plan illustrate that his wife's advice does not? many decisions are made on the margin. people usually exploit opportunities to make themselves better off. resources are scarce. all costs are opportunity costs.

Oakmont company has an opportunity to manufacture and sell a new product for a four-year period. the company’s discount rate is 18%. after careful study, oakmont estimated the following costs and revenues for the new product: cost of equipment needed $ 230,000 working capital needed $ 84,000 overhaul of the equipment in year two $ 9,000 salvage value of the equipment in four years $ 12,000 annual revenues and costs: sales revenues $ 400,000 variable expenses $ 195,000 fixed out-of-pocket operating costs $ 85,000 when the project concludes in four years the working capital will be released for investment elsewhere within the company. click here to view exhibit 12b-1 and exhibit 12b-2, to determine the appropriate discount factor(s) using tables.