Oooooooookay! I have a math problem to solve and I've really cracked my head on it but my efforts were to no avail. Guess i'm really a maths retard. Can some kind geniuses out there pls help?
Question:

Question:

There is an old saying in iaido - "Kachi wa saya no naka ni ari" = "Victory comes while the sword is [still] in the scabbard".