Answer:
$7.79
Explanation:
The price level that should be choose in order to maximize the profit is $7.79
As when there is a price fixing that lies between the two rivalrs so if one rivalr select to fix the price it should not be more than the rivalr marginal cost i.e. price and it is more than the price .
here the price fixing is $10 so the price level would be less than the rivalr price and more than the marginal cost
Therefore it is $7.79