The University Store, Inc. is the major bookseller for four nearby colleges. An income statement for the first quarter of the year is presented below: University Store, Inc. Income Statement For the Quarter Ended March 31 Sales $ 800,000 Cost of goods sold 560,000 Gross margin 240,000 Selling and administrative expenses Selling $100,000 Administrative 110,000 210,000 Net operating income $ 30,000 On average, a book sells for $40.00. Variable selling expenses are $3.00 per book; the remaining selling expenses are fixed. The variable administrative expenses are 5% of sales; the remainder of the administrative expenses are fixed. The cost formula for selling and administrative expenses with "X" equal to the number of books sold is: Multiple Choice = $105,000 + $5X Y = $110,000 + $33X = $105,000 + $3x Y = $110,000 + $5X