Answer
All real numbers are solutions.
The graph is shown below.

Work Step by Step
The given inequality is
$\Rightarrow 3r-8 \gt 3(r-6)$
Use distributive property.
$\Rightarrow 3r-8 \gt 3r-18$
Add $18$ to each side.
$\Rightarrow 3r-8 +18\gt 3r-18+18$
Simplify.
$\Rightarrow 3r+10\gt 3r$
Subtract $3r$ from each side.
$\Rightarrow 3r+10-3r\gt 3r-3r$
Simplify.
$\Rightarrow 10\gt 0$
The inequality is true.
Hence, all real numbers are solutions.