A truck salesperson is quoted as follows: "Even though our list price has gone up to $42,000, I'll sell you a new truck for the old price of $40,000, an immediate savings of $2,000, and give you a trade-in allowance of $21,000, so your cost in only ($40,00021,000)=$19,000. The book value of your old truck is $12,000, so you're making an additional ($21,00012,000) =$9,000 on the deal." The salesperson adds, "Actually I am giving you more trade-in for your old truck than the current market value of $19,500, so you are saving an extra ($21,00019,500)=$1,500., a. In a proper replacement analysis, what is the first cost of the defender? b. In a proper replacement analysis, what is the first cost of the challenger