15 ft
Explanation
you can easily solve this by using a rule of three
Step 1
Let x represents the actual length of the wall in feet
is
[tex]1\text{ inc}\rightarrow3\text{ ft}[/tex]then
[tex]5\text{ in}\rightarrow x[/tex]as the proportion is the same
[tex]\begin{gathered} \frac{1}{3}=\frac{5}{x} \\ \text{cross multiply} \\ x\cdot1=5\cdot3 \\ x=15\text{ ft} \end{gathered}[/tex]so, the answer is 15 ft
I hope this helps you
