Answer:
15
Step-by-step explanation:
This is an algebraic problem.
The amount at start is [tex]11\frac{1}{2}[/tex] gallons
Then bought additional gasoline: [tex]+ 6\frac{4}{5}[/tex]
The remainder after the trip = [tex]3\frac{3}{10}[/tex]
Then the amount of gas used is given by x.
This gives an equation: [tex]11\frac{1}{2} + 6\frac{4}{5} - x = 3\frac{3}{10}[/tex]
solving for x gives 15
