Quiz questions can easily be removed from quizzes that have not been taken by students and graded. Single questions can be deleted from the Editing quiz page. Currently, multiple questions cannot be removed at one time.
Deleting quiz question(s)
Click the link to the quiz on the course home page.
In the Administration block, under the Quiz Administration menu, click Edit quiz.
Locate the question and click the Delete icon for that question.
Click Save near the top of the Editing Quiz page.
Once a quiz has been taken, you are not allowed to delete a question. For other options on how to handle a quiz that students have taken and a question should have been thrown out, see Edit Questions in a Graded Quiz.