Each successive week, add 5 reps to the lunges, 3 reps to the push-ups, and 1 rep to the pull-ups.
Each successive week, add 5 reps to the lunges, 3 reps to the push-ups, and 1 rep to the pull-ups. So your week 2 would be 25 lunges, 18 push-ups, and 11 pull-ups. Week 3 would be 30 lunges, 21 push-ups, and 12 pull-ups, etc.