Marion, (are you also "Guest Marion?")

(1)Re the Cards, Guest Marion said: << There are three red sides. Of those three, two have red on their opposites, and one has white on its opposite. >>

There are TWO cards which can have Red as the top surface. Of these, ONE has white on the bottom, ONE has Red on the botton.If you can see red side, on top, you can eliminate the W/W card. i.e. you KNOW this is NOT the W/W card. Therefore it must be EITHER the R/R card, or the R/W card. 50/50 chance. If it is the R/R card, then the side you cannot see is RED, If it is the R/W card, then the side you cannot see is WHITE. So again, 50/50