Each of The Bottom Line sections in the chapters suggest exercises to deepen skills and understanding. Sometimes there is only one possible solution, but often you are encouraged to use your skills and creativity to create something that builds on what you know and lets you explore one of many possible solutions.
There are relatively few global mental ray preferences for mental ray, and they primarily affect the visibility of render buckets and the functionality of the mental ray Messages window.
Change the mental ray preferences to allow logging of render-time information.
Enable mental ray for your current scene.