Given a rectangle with dimension l by w, then
[tex]\text{ area of the rectangle = }l\times w[/tex]Since the room is rectangular, then
[tex]\text{ area of the room = }20\times10=200ft^2[/tex]fractional increase = increase / (original area)
the increase = 200 square feet,
and the original area of the living space = 1000 square feet.
Therefore,
[tex]\text{ fractional increase = }\frac{200}{1000}=\frac{2}{10}=\frac{1}{5}[/tex]The correct option is C
