Nanjo's Puzzle: 20

[prof]

And if you subtract 20 from 130, you get 110. That's the emergency number for calling the police.
Splendid! That is correct. I knew you were a quick thinker, Ange.
Oooooohh, well done, Angeeeeeee! What a wise granddaughter I have!
Congratulations. This medal belongs to you.
But... what was that about the difference between the two being half an emergency?
Heheh, yeah, we didn't really need that part. If you use that hint, you could make a pretty good guess at the answer even if you forgot what the emergency numbers were.
Huh?



Yes, that's the spirit. Let's solve more and more!