You are in charge of purchases at the student-run used-book supply program at your college, and you must decide how many introductory calculus, history, and marketing texts should be purchased from students for resale. Due to budget limitations, you cannot purchase more than 850 of these textbooks each semester. There are also shelf-space limitations: Calculus texts occupy 2 units of shelf space each, history books 1 unit each, and marketing texts 5 units each, and you can spare at most 1,500 units of shelf space for the texts. If the used book program makes a profit of $20 on each calculus text, $8 on each history text, and $16 on each marketing text, how many of each type of text should you purchase to maximize profit?

You would like to purchase one class a share of berkshire hathaway through your scottrade brokerage account. scottrade charges a ​$6 commission for online trades. you log into your​ account, check the​ real-time quotes for berkshire hathaway​ (you see a bid price of ​$262 comma 900 and an ask price of ​$263 comma 730​) and submit your order. a. what is the current​ bid/ask spread for berkshire hathaway class a​ shares? b. if scottrade routes your buy order to the​ nyse, where berkshire hathaway is​ listed, what's the potential minimum your total transaction costs will​ be? c.​ if, instead, scottrade routes your buy order to​ nasdaq, where berkshire hathaway is not​ listed, what's the potential maximum your total transaction costs will​ be? d. regardless of how your trade is​ executed, based on the​ bid/ask spread, what is the market value of your​ trade? a. the current​ bid/ask spread for berkshire hathaway class a shares is ​$ nothing. ​(round to the nearest​ dollar.)