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   Show do Milhão, the Brazilian version of Who Wants to Be a Millionaire?, differs from the American version in a few crucial ways. For one, you get half the money won from previous questions as a consolation prize. The audience (of "ask the audience" fame) consists, Price is Right-like, of contestants waiting their turn to play. You can stop at any time instead of answering and get all the money you would have on up till that point. Barring the million dollar prize, of course. Also, the prize money is usually given in gold bars, which is awesome. But none of those differences are why I'm talking about it now.

   Yesterday I had discussed the Monty Hall problem and how it applied to 50:50 on Who Wants to Be a Millionaire?. In Show do Milhão their equivalent of 50:50 is a lifeline called "the cards." Pick a card, any card, out of the four cards face down in front of you. If you pick a three, three wrong answers are eliminated, if you pick a two, two wrong answers are eliminated, an ace, one wrong answer, a king, no wrong answers. Does this change the math?

   At first blush, you'd think not: there's a 25% of each, right? Half favorable and half unfavorable. That averages out to 50%. But think twice about that. When you select a 50:50, there's a 100% chance of having a 50% chance on a blind guess, which means a 50% chance of guessing correctly. When you select the cards, it's not 50%, though there's a one-in-four chance of each- 25% of having all wrong answers eliminated, but 25% of having none, et cetera. If you have one wrong answer eliminated and had to guess blindly between the other three, there's a one in three chance you select the correct answer. There's 25% chance you get a 25% chance (no answers eliminated, four answers left,) 25% chance you get a 33.333% chance (one answer eliminated, three answers left,) 25% chance you get a 50% chance (two answers eliminated, two answers left,) and a 25% of you get a 100% chance (three answers eliminated, one answer left.)

   Another counter-intuitive solution: mathematically that boils down to, no a 50:50 proposition, but a little over a 52:48 proposition, your favor.