Question

a gasoline tank is $\frac78$ full. after $12$ gallons have been used, it is half full. how many gallons does this tank hold when it is full?

Answer 1

32

Explanation:

Let $x$ represent the number of gallons the tank holds when it is full. We know that the difference between $\frac78$ full and $\frac12$ full is 12 gallons, so we set up an equation and solve for $x$.

12=(7/8)x-12x

12=(3/8)x

12*(8/3)=x

32=x

The tank holds $\boxed{32}$ gallons when it is full.