1. You are going on vacation in New Zealand, and you found you need a transformer to convert New Zealand's standard 240V to the American's standard 120V so you can use and charge your laptop and your cell phone while you are there.
2. Make the necessary calculations and find the ratio of turns in the primary and secondary coils of your transformer and the ratio of input to output current.
3. In your second post, also include your answer for the question: How could a New Zealander traveling in the United States use this same transformer to power his 240V appliances from 120V?