Take into account that the volume of the code of paint is:
[tex]V=A\cdot w[/tex]where A is the surface area and w is the thick of the code of paint (w = 10 mm).
Consider that the previous volume V is determined by the amount of pain. In this case, there is 1 gallon of paint, which in units of ft^3 is:
[tex]1\text{gal}=0.1605ft^3[/tex]Now, consider also that 10mm in units of feet is:
[tex]10mm\cdot\frac{1m}{1000mm}\cdot\frac{3.28ft}{1m}=0.0328ft[/tex]In the equation V = A*w, solve for A, replace the values of V and w in feet, and simplify:
[tex]A=\frac{V}{w}=\frac{0.1605ft^3}{0.0328ft}\approx4.89ft^2[/tex]Hence, 1 gallon of paint will cover a surface area of approximately 4.89ft^2.
