Question

a gas tank that is 1/3 full requires 6 gallons to make it 5/6 full.what is the capacity of the tank in gallons.

Answer 1

1/3 x + 6 = 5/6 x
6 = 1/2 x
x = 12

Check:
the 1/3-full tank has 4 gallons. Adding 6 makes 10 gallons, or 5/6 of 12