Question instances report
From MoodleDocs
Settings > Site administration > Report > Question instances
This report lists all the places a specific question type is used. It provided a list by course show the total, visible and hidden number of that question type.
For example in demo.moodle.org the Moodle Features Demo (Japanese) shows the multiple choice question is visible in 1 instance. The ICT ensamenieving course uses it 30 times, 29 are visible and 1 is hidden.