# Kakegurui another math help request

In Kakegurui manga chapter 3, Yumeko bet all her 40 chips on number 24 and she claimed that if the sword happened to face up on number 24, Yuriko would lose with the total debt of 21億7000万円. How to get this number?

Based on my understanding, both players agreed to bet 40 chips in this round. So if Yumeko is lucky, she would earn 30*40=1200 chips (I assume these chips come from Yuriko's side? If so, she would lose 1200 chips in exchange). The chip difference between these two players would be (40+1200)-(40-1200)=2400. So since each chip is worth 100万円, Yuriko will lose with debt totalling 24億円...

Where did I make a mistake?

• If you say you answered your question, you could post it as an answer (and I think you can accept it too, but I don’t know if you get rep from that). Commented Jul 22 at 16:51

I reread the story and it appears to me that I overlooked the fact that Yuriko bet 5 chips on 24 as well.

So suppose the sword is facing up on 24.

According to the rules,

Yumeko gains 30*40=1200 chips, while Yuriko loses 1200 chips.

Yuriko gains 5*30=150 chips, while Yumeko loses 150 chips.

So the chip difference is now (40+1200-150)-(40+150-1200)=2100.

Also there is another rule that states that any chips that "missed target" (外れ) will go to opponent. In this case, since Yuriko already placed 5 chips in 7 other numbers, she must hand over Yumeko 5*7=35 chips.

Now the final chip difference is (40+1200-150+35)-(40+150-1200-35)=2170, which is worth 21億7000万円 as expected.