fractions

 

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?  

 

 

Note that 1/2 is the same as 3/6.  

 

So 2 gallons took the tank to 3/6 from 1/6.  

 

So 2 gallons added 2/6.  That means 1 gallon is 1/6.  

 

Therefore, the total capacity of the aquarium is 6 gallons.  

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