You might want to give a penalty for incorrect answers in your exams. Here's how you can set that up!
To add questions with negative scoring in exams, you need to select the multiple choice question type and select more than one answer as correct.
When you select several answers as correct answers in a multiple-choice question, an extra setting for this will appear at the bottom of the page.
If you select Comprehensive or Guessing penalty, a penalty will be given for each incorrect answer. Read more about the scoring for multiple correct answers.