<p><a href="https://www.prepswift.com/quizzes/quiz/prepswift-combinations" target="_blank">Combinations Exercise</a></p>
<p><strong>NOTE</strong>: about 3:18 into the video, Greg says something on the lines of "you'll shake hands with 435 people". Clearly he meant to say that "there will be 435 handshakes in total"</p>