The study of economics would be superfluous if __________ did not exist

Patty spends $10 a week on bagels and soda. The price of a bagel is $2 and the price of soda is $1 a can. Patty buys 2 bagels and 6 cans of soda. Her marginal utility from bagels is 20 units

The price of a bagel rises to $3 and the price of a can of soda rises to $1.50. Patty now buys ________ bagels and her marginal utility from bagels ________. She buys ________ cans of soda and her marginal utility from soda ________. A) fewer than 2; increases; fewer than 6; increases B) 2; is 20 units; 6; is 10 units C) fewer than 2; is 20 units; fewer than 6; is 10 units D) fewer than 2; decreases; fewer than 6; decreases

Using marginal analysis, explain why many restaurants and coffee shops offer low-cost refills on beverages (for example, a shop may charge $1.50 for a cup of coffee and only $.50 for a refill)