Let \(y = \frac{5}{1 - 3x}\).

Rearrange to make \(x\) the subject:

\(3x = 1 - \frac{5}{y}\)

\(3x = \frac{y - 5}{y}\)

\(x = \frac{y - 5}{3y}\)

Thus, \(f^{-1}(x) = \frac{x - 5}{3x}\) or \(\frac{1}{3} - \frac{5}{3x}\).

The range of \(f\) is \(x \geq 1\), so the domain of \(f^{-1}\) is \(-2.5 \leq x < 0\).

The domain of \(f\) is \(x \geq 1\), so the range of \(f^{-1}\) is \(x \geq 1\).