質問: "what is the value of 0.420420420... - 0.240240240...?" "what is the value of 0.420420420... - 0.240240240...?"
回答: "calculation: ⇒ 0.420420420....- 0.240240240..... ⇒ 420999 - 240999 ⇒ (420-240)999 ⇒ 180999 ⇒ 20111 ∴ the value of 0.420420420....- 0.240240240..... is 20111."