Investigating geometric optics, interference, and diffraction.
: The 3rd edition added about 550 new "Additional Exercises" at the ends of chapters, which are notably not keyed to specific sections to encourage better conceptual synthesis. --- University Physics Harris Benson 3rd Edition Answer
If you were stuck, don’t just copy the answer. Understand why a particular formula was chosen (e.g., why was used instead of Investigating geometric optics