The first thing you want to do is make the fractions improper . Then what you want to do next is add up the gallons of gas she used from her home to her grandparents' home and the gas she used from her grandparents' home to her cousins and you see what 21/5 + 41/10 is and you get 8.3 , So that's means she used 8.3 miles of gas and she has 15.3 gallons of gas left over because she started out with 23.3 miles .
