Answer:
David's car gives mileage 7 miles per gallon
Explanation:
David drives in a week = 168 miles.
He fills his gas tank twice a week, each fill up is for 12 gallons = 12 Ă— 2 = 24 gallon per week
To calculate the mileage of David's car we use the formula
Gas mileage =

=

= 7 miles per gallon
David's car gives mileage 7 miles per gallon