Can I create a quiz and then could duplicate it to modify for individual students?
There currently isn't a quick method to simply duplicate a quiz. However, you should be able to export a quiz and then reimport it to get your copy. Here are the steps I'd try:
When it finishes you should have two copies of the same quiz and you can edit them independently. To assign one of the quizzes to select students, in the Assign To section of the quiz settings, remove Everyone and insert just the names of the students who are to take this copy.
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