Chapter 2 - Equations, Inequalities, and Problem Solving - 2.4 Applications with Percent - 2.4 Exercise Set - Page 111: 90

$-3$

$\bf{\text{Solution Outline:}}$ Interchange the numerator and the denominator to get the reciprocal of the given expression, $ -\dfrac{1}{3} .$ $\bf{\text{Solution Details:}}$ Interchanging the numerator and the denominator, the reciprocal of the given expression is \begin{array}{l}\require{cancel} -\dfrac{3}{1} \\\\= -3 .\end{array}