Question instances report
From MoodleDocs
An administrator can generate a question instances report in Settings > Site administration > Report > Question instances. The Manager can also generate this report.
This report lists all the places a specific question type is used. It provides a list by course that shows the total, visible and hidden number of that question type. Clicking on a course title link will take you to the relevant question in the question bank for the category/course.
One practical use of this report is to find questions that may have inadvertently been created in a course which should have been created at the System default or a particular category level.
