the distance traveled in a car varies directly as the amount of gasoline used. if a car travels 520 miles and uses 26 gallons of gas, find the constant of variation or miles per gallon.

Zachary has been trying to work on an essay for almost three hours, be he can't seem to focus for more than 15 or 20 minutes at a time. what should he do so that the quality of his work doesnt suffer because of poor concentration and lack of energy