An aquarium tank is 1/6 full of water. When 2 gallons of water are added, the tank becomes 1/2 full. What is the total capacity of the aquarium tank, in gallons?
Let the capacity of a full tank ==T
1/2 - 1/6 ==1/3 - this is equivalent to 2 gallons.
1/3T == 2
T ==2 / (1/3) ==6 glallons - the capacity of the tank when full