第4問

A magician has one hundred cards 数ed

1

へ

100

. He puts them inへthree boxes, red, white およびblue, 各nonempty. A member selects two boxes, chooses one card からeach, およびannounces their 和. Given thは和, magician identifies box からwhich no card was chosen. How many assignments のcards へthree boxes make thはalways possible?

ステップ 1/5: Encode condition

前のステップ次のステップ

A+B,\quad B+C,\quad C+A\text{ pairwise disjoint}.

詳しい解説

A repeated 和 would give two possible omitted boxes.