1. Say three answers of 6 need to be selected, set the grades of the wrong ones to be -100%, like this:
a) 33%
b) -100%
c) 33%
d) 33%
e) -100%
f) -100%
2. Create Random Questions in each category, then add them to the quiz. You can choose three questions from category A, for example, and five category B.