Amazon Software Development Test Engineer interview questions

k closest points to origin out of N on a map

How do you test the functionality of weather.com which takes a coordinates anywhere on earth and gives you accurate current weather information. After I given my plan which is to use automation tool collecting weather information from public weather station and compare results. I was asked what if there's no web service, no phone service, not even radio and you can't load weather forecast information from the public weather stations. Nor you can use historical value to test since the results need to be very accurate.