150miles per week 25 miles per gallon 3 dollars per gallon
[tex] \frac{150miles}{1week}* \frac{1 gallon}{25miles}* \frac{3 dollars}{1 gallon} =$18 dollars per week [/tex] (mile and gallons, since the are both on the top and bottom of the fraction cancel out, leaving us with dollars per week)
