This is fair. But I'm not prescribing specific numbers, just using them as examples. The point is to pick something achievable. So, you can do this: 3 reps of

This is fair. But I'm not prescribing specific numbers, just using them as examples. The point is to pick something achievable. So, you can do this: 3 reps of each exercises (push-up, pull-up, sit-up). Perform this circuit 4 times for 2 weeks. Is it getting easier? If so, increase reps, or do the specific exercise slower (time under tension). Lots of ways to build.