Answer
$\frac{1}{48}$
Work Step by Step
Slope is $\frac{rise}{run}$.
Because plumbers recommend that sewer pipe is sloped $0.25$ inches for every foot, express this as a ratio.
$0.25$ inches represents the $rise$.
$12$ inches represents the $run$.
$\frac{0.25 inches}{12 inches}$
$\frac{0.25 inches}{12 inches}=\frac{1}{48}$
