Set up before a clock, and every minute on the minute perform 5 pull-ups, 10 push-ups, and 15 squats. Can you continue for thirty minutes? Twenty minutes? How about 10? Post results to comments. If you fall behind the clock keep going for thirty minutes and see how many rounds you can complete.
If you've finished the workout before this time add +1 to each exercise, i.e., 6 pull-ups, 11 push-ups, and 16 squats each minute, and see if you can go the full thirty minutes. We've seen +3. Any +4's?
Post rounds completed and Rx to comments.