Base
The output appears here. (hopefully...)
Two trains are leaving for Tokyo. Train 1 travels 200 kph and will reach Tokyo in 2 hours. Train 2 is newer and can travel faster. A bird lands on the track and delays Train 2.
The app calculates how fast Train 2 needs to travel in kph to arrive at Tokyo at the same time as Train 1 given the number of minutes Train 2 is delayed by.