In Classic Quizzes, you can use the Rich Content Editor to edit the quiz description or quiz questions.
You can access the Rich Content Editor to edit a quiz description when adding a new quiz or editing a quiz.
To add a new quiz, click the Add Quiz button [1]. To edit a quiz, click the quiz's Options icon [2] and select the Edit option [3].
Note: New Quizzes utilizes a separate Rich Content Editor.