Your firm sells club soda at the price of 1$ each in both grocery stores and convenience stores. You have a budget of $550 for store displays, and must decide how to allocate this budget between grocery stores and convenience stores to maximize the total number of sales. The following table shows the total number of units that can be sold in grocery stores and convenience stores, according to the number of displays in each type of store. Displays in grocery stores cost $150 each and displays in convenience stores cost $100 each. 3 / 6 Number of displays in grocery stores Total number of units sold in grocery stores Number of displays in convenience stores Total number of units sold in convenience stores 1 2 3 4 5 6 500 900 1,250 1,550 1,750 1,850 1 2 3 4 5 6 400 780 1,130 1,460 1,760 1,960 a. With $550 to spend, the total number of units sold will be maximized by choosing ______ displays in grocery stores and ______ displays in convenience stores. With $550 to spend, the maximum number of units that can be sold is ________.

 b. Suppose your firm can spend $1,200 on store displays. The total number of units sold will be maximized by choosing ______ displays in grocery stores and ______ displays in convenience stores. The maximum number of units that can be sold is ________ (Hint: Recall that you maximize your sales when the last dollar spent on displays gives the same marginal utility – namely the same marginal revenue from the sales - in both displays).

 c. Show the calculations you have made to reach those conclusions.