 Two envelopes problem

The Two Envelopes Problem is a classic problem in probability and decision theory that involves a situation with two envelopes, each containing a certain amount of money. The main premise is as follows: 1. You have two envelopes (let's call them Envelope A and Envelope B). One envelope contains twice as much money as the other. You do not know which envelope contains the larger amount. 2. You are allowed to choose one envelope to keep.