In the progress report
Go to the Tasks tab in your class.
On the task containing the custom quiz, click on the student completion summary.
In the Overview and Marks tabs, you can see who has completed the quiz, how your students have performed, and which questions were the most challenging.
In mark book
You can learn more about viewing quiz results in mark book in our guide to getting started with mark book.
To learn more about using this data in your classroom, check out our guide to informing your teaching with data.