Answer:
5 inches
Step-by-step explanation:
we know that
The scale drawing is
[tex]\frac{1}{4}\ in : 1\ ft[/tex]
using proportion find out the width of the great room on her plan
[tex]\frac{(1/4)}{1}\ \frac{in}{ft}=\frac{x}{20}\ \frac{in}{ft}\\\\x=20(1/4)\\\\x=5\ in[/tex]