Trim or delete: which seconds remain?

This duration model explains selection boundaries. It does not play or edit audio, and it is not an iPhone screen. A 60-second original has introduction 0–12, useful passage 12–42 and closing 42–60.

Selection start, seconds Selection end, seconds Choose an operation.

Try 12 to 42: Trim keeps a 30-second passage; Delete keeps the introduction and closing, joined to total 30 seconds. Equal duration does not mean equal content. Try 12 to 50 next: Trim keeps 38 seconds; Delete keeps 22.

Original HowCurio practice material. No account, upload or device control. Entries stay in this page and reset on reload.