You can add negative marking for one or more quiz questions
Open up any of your quiz question and scroll to the bottom
Here you will see the option to add points
Add + and − points.
For example, let's say you add points + 1 and -0.25
Now when your users attempt the question, they get 1 point for a right answer and -0.25 for a wrong one
The overall score of a user is calculated as
(Total of all + points) − (Total of all − points)