Notice that to get maximum exposure the display must be equidistant to all three entrances.
See solution.
Practice makes perfect
We are given that a bookstore clerk wants to set up a display of new books and he want the display to get maximum exposure. Let's take a look at a simplified diagram of this situation.
To get maximum exposure the display must be equidistant to all three entrances. This means that the points that represent entrances must lie on a circle centered at a point representing the display.
