The formula for the length of the perpendicular from the origin to a line \( Ax + By + C = 0 \) is:
\[
{Length} = \frac{|Ax_1 + By_1 + C|}{\sqrt{A^2 + B^2}}
\]
The equation is \( \frac{x}{5} - \frac{y}{12} = 1 \), which can be rewritten as:
\[
\frac{x}{5} - \frac{y}{12} - 1 = 0 \quad {where} \, A = \frac{1}{5}, B = -\frac{1}{12}, C = -1
\]
Thus, the length of the perpendicular is:
\[
\frac{|0 + 0 - 1|}{\sqrt{\left( \frac{1}{5} \right)^2 + \left( -\frac{1}{12} \right)^2}} = \frac{1}{\sqrt{\frac{1}{25} + \frac{1}{144}}} = \frac{1}{\sqrt{\frac{169}{3600}}} = \frac{60}{13}
\]