English Dictionary

two envelopes problem

固有名詞

A puzzle of this kind: "You are given two indistinguishable envelopes, each containing money; one contains twice as much as the other. You may pick one envelope and keep the money it contains. Having chosen an envelope at will, but before inspecting it, you are given the chance to switch envelopes. Should you switch?" Because you stand to gain twice as much money if you switch while risking only a loss of half of what you currently have, it is possible to argue (fallaciously) that it is beneficial to switch.

日本語の意味

「two envelopes problem」とは、区別のつかない2つの封筒があり、そのうち1つにはもう1つの封筒に入っている金額の2倍の金額が入っているという状況が設定されたパズル（数学的・論理的な問題）です。1つの封筒を選んだ後、中身を確認する前に封筒を交換する機会が与えられ、交換することで理論上倍の利益を得る可能性がある一方、実際には矛盾やパラドックスが生じることを議論する問題です。

In his philosophy seminar, he debated the two envelopes problem to illustrate decision-making under uncertainty.

彼は哲学のゼミで、意思決定の不確実性を示すために二つの封筒のパラドックスを議論した。

意味（1）

A puzzle of this kind: "You are given two indistinguishable envelopes, each containing money; one contains twice as much as the other. You may pick one envelope and keep the money it contains. Having chosen an envelope at will, but before inspecting it, you are given the chance to switch envelopes. Should you switch?" Because you stand to gain twice as much money if you switch while risking only a loss of half of what you currently have, it is possible to argue (fallaciously) that it is beneficial to switch.

the two envelopes problem （ canonical ）