### Comments (3)

**Nigel said: (85 months ago)**

Take the other envelope.

**Chris said: (85 months ago)**

Sure - but the conundrum is, why does this defy common sense that it shouldn't matter?

**huxley said: (84 months ago)**

a lot depends on your personality type

One factor you don't mention is if you keep the first envelope you have a 100% chance of winning $20.

If you take the other envelope, you have a 50% of losing $10 and a 50% chance of gaining $20. You are trading off certainty for a potential gain (a gain which isn't enough to overcome most people's risk-aversion).