Hi Daniela L.
6048 in3
According to your information, the base of the tank is a rectangle per the given relationship between the Length and Width.
Perimeter of the Base = 96
Perimeter of the Rectangular Base = 2*Width + 2*Length
Area of the Rectangular Base = Width * Length
Volume of a Rectangular Prism = Area of the Base * Height = Bh = V
Volume of a Rectangular Prism = Length*Width*Height = V
Given that the tank is 14 inches tall, let this represent the height, H
H =14
Since volume is Area of the Base times the height also, Length * Width* Height, you will need you need calculate the dimensions of the Rectangular base from the perimeter given for this base
Perimeter = 96
Perimeter of a Rectangle = 2*Width + 2*Length
Given the Length is 3*Width
Let W = Width
Let L = Length = 3*Width = 3*W
Substituting we have:
96 = 2*W + 2*(3W)
Divide both sides of the equation by 2
48 = W + 3W
48 = 4W
Divide both sides by 4
12 = W
L = 3*W = 3*12 = 36
Checking the numbers,
Perimeter of the Rectangular Base is 96
2*12 + 2* 36 = 24 + 72 = 96
Area of the Rectangular. Base is 12 * 36 = 432
Volume of the Rectangular Tank
432 * 14 = 6048 in3
Also
12 * 36 * 14 = 6048 in3
I hope this helps