Answer:
27
Step-by-step explanation:
Let T be the capacity of the tank.
Since the tank was 1/3 full and ends up 7/9 full.
[tex]\frac{7}{9}[/tex]T - [tex]\frac{1}{3}[/tex]T = 12
Simplifying the left side of the equation, tells us how much 12 gallons fills.
[tex]\frac{4}{9}[/tex]T = 12
Now we solve for T:
T = 12*9/4
T = 27
