Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2026 — Part 10 Question 82

Math Olympiad Vault · MathNet 2026 — Part 10

Question 82

Aerith has written down two letters on a piece of paper. Bob will pick a positive integer and she'll try to factor Bob's positive integer into two others, such that when spelled in English, one contains her first letter and the other her second.
For example, if Aerith had chosen letters "v" and "w" and Bob chose "ten", she could spell it out as "five" times "two," but would fail if Bob chose "twenty".
Show that there is a unique pair of letters Aerith can choose that allows her to succeed no matter what number Bob picks.