Start finding the area of the room
[tex]15ft\cdot25ft=375ft^2[/tex]
then, using the cost per sq. ft, multiply them both and find the cost for carpeting the total area of the room in both situations.
for the first situation:
[tex]375ft^2\cdot\frac{2.88}{1ft^2}=\text{\$}1080[/tex]
for the second situation:
convert the cost that is given in sq. yds to sq. ft using the conversion factors
[tex]\text{\$}\frac{21.5}{yd^2}\cdot\frac{1yd^2}{9ft^2}=\text{\$}\frac{2.39}{ft^2}[/tex]
then, multiply by the area
[tex]375ft^2\cdot\frac{2.39}{1ft^2}=\text{\$}896.25[/tex]
The cost for the cheaper carpet is $896.25