Question

A gallon of water is equal to 231 cubic inches. How many gallons of water are needed to fill a fish tank that measures 11" high, 14" long, and 9" wide?

Answer 1

we know that

[volume of a fish tank]=11*14*9-------> 1386 in³

if  1 gallon--------------> 231 in³
X------------------------> 1386 in³
X=1386/231-------> X=6 gallon

the answer is
are needed 6 gallons of water to fill a fish tank