Read each request and inspect the starting state before choosing a command. Explain the relevant boundary to yourself: which records belong, which file can change and which earlier result must survive. These are original practical tasks, not copied employer or certification questions. A valid alternate command sequence is accepted when it produces the same result. The harder tasks combine selection, preservation and failure handling. Use the hint only after you have identified the likely mistake. In a timed screen, prioritize a complete correct handoff and inspect the final state before submitting.