Answer
12
Work Step by Step
Since the person is buying a unit AND a keyboard AND a printer, we use the multiplication rule: there are 3(2)(2) = 12 distinct systems.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.