#senku math tutor real?!

[ask-senku-ishigami]

Two ships are 10 km apart on a line running from south to north. The one farther north is streaming towards west at 20 kmph. The other is streaming towards north at 20 kmph. The time taken to reach the position of closest approach is?

15 minutes. And the distance will be 5√2 km.

I would elaborate more on why this works, but that's probably not what you were looking for, and I'm not good with words. Maybe if enough people ask... or you can just find it online.

Let me know if you have any more questions.