## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

When the number of people (x) increases, the time needed (y) decreases. If this is a case of inverse variation, then $y=\displaystyle \frac{k}{x}$, for some CONSTANT k. The first case has $x=2, y=5$, leading to $k=xy=10.$ The second case has $x=10,y=4$, leading to $k=xy=40.$ Since k is not constant, this situation does NOT represent inverse variation.