For a recent year, McDonalds (MCD) company-owned restaurants had the following sales and expenses (in millions):

Sales	$29,900
Food and packaging	$(10,474)
Payroll	(7,500)
Occupancy (rent, depreciation, etc.)	(6,626)
General, selling, and administrative expenses	(4,400)
	$(29,000)
Operating income	$900

Assume that the variable costs consist of food and packaging, payroll, and 40% of the general, selling, and administrative expenses.

a. What is McDonald's contribution margin? Round to the nearest million. (Give answer in millions of dollars.) $fill in the blank million

b. What is McDonald's contribution margin ratio? fill in the blank %

c. How much would operating income increase if same-store sales increased by $1,800 million for the coming year, with no change in the contribution margin ratio or fixed costs? Round your answer to the closest million. $fill in the blank million