The dimension for the first room is
[tex]=12ft\text{ by 12ft}[/tex]By conversion,
[tex]1squareyard=0.111\text{ square f}eet[/tex]The area of the first room will be
[tex]\begin{gathered} =l\times b \\ =12ft\times12ft \\ =144ft^2 \end{gathered}[/tex]The second room has a dimension of
[tex]=10ft\text{ b}y\text{ 14ft}[/tex]The area of the second room will be
[tex]\begin{gathered} =l\times b \\ =10ft\times14ft \\ =140ft^2 \end{gathered}[/tex]The dimension of the third room is
[tex]21ft\text{ by 20ft}[/tex]The area of the third room will be
[tex]\begin{gathered} =l\times b \\ =21ft\times20ft \\ =420ft^2 \end{gathered}[/tex]The total area of the three rooms will be
[tex]\begin{gathered} =144ft^2+140ft^2+420ft^2 \\ =704ft^2 \end{gathered}[/tex]Recall that
[tex]\begin{gathered} 1squareyard=0.111\text{ square f}eet \\ 1squareyard=\frac{1}{9}ft^2 \end{gathered}[/tex]The final answer to be converted to the squared yard would be divide by 9
[tex]\begin{gathered} =\frac{704}{9}sq\text{ yd} \\ =78.222\text{ sq yd} \\ \approx\text{ to the nearest tenth= 78.2 sq yd} \end{gathered}[/tex]Hence,
The number of square yards of carpet to be ordered = 78.2 sq yd