Generate a comprehensive practice problem set for {{topic}} at the {{target_audience}} level, using a {{tone}} tone, to prepare for {{goal}}. Include three difficulty tiers: warm-up (3 problems), intermediate (4 problems), and challenge (3 problems). Each problem must have hints and solutions. Also provide a self-assessment rubric and answer key summary. Total output: 2000–2500 words. Use plain language. Skip any section if information is unknown. Paste any relevant background information after these instructions before running.