I'm trying to get a grasp on this stuff too, so this new forum is really timely. I'm sure I'll muck some of this stuff up, but here goes.


I think you've got this one backwards; it should be 6 of 47, or 6/47 = .128 or 12.8%.


And I think to get the chance of making it in two cards, you work with the chance of not making it, and subtract it from 1, like so:


1 - 41/47 * 40/46 = .241 or 24.1%


Which is pretty darn close to your estimate.