Find a digit that makes _ 2,440 divisible by 9

Country carpets charges $22 per square yard for carpeting, and an additional installation fee of $100. city carpets charges $25 per square yard for the same carpeting, and an additional installation fee of $70

Subtract 8 1/6 - 4 5/6 . simplify the answer and write as a mixed number.

How can we find the measure of an exterior angle if we know the measurement of an interior angle