Contribution Margin and Contribution Margin Ratio

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

Sales

Food and packaging

Payroll

$\frac{\text{\$}15,800}{\text{\$}(4,402)}$

Occupancy $($rent$,$ depreciation, etc.$)$

$(4,000)$

$(4,628)$

General, selling, and administrative expenses

$\frac{(2,300)}{\text{\$}(15,330)}$

Operating income

$$470$

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.$)$

$$,$ million

b$.$ What is McDonald's contribution margin ratio?

$\%$

c$.$ How much would operating income increase if same$-$store sales increased by $$900$ million for the coming year, with no change in the contribution margin ratio or fixed costs? Round your answer to the closest million.

$ million