One of a Continuing Series

This site needs some entertainment. I have a series of so-called Quiz Questions, and I will post one from time to time.

I am guessing the problem involves turning over the least number of cards. Post your answer in the comments section below before viewing the video.

Now I have actually viewed the video, and there is an additional proviso I did not state above. That is all cards have a letter on one side and a number on the other side. Now solve the problem with that in mind. It really is easy.

My solution is posted on the Skeptical Analysis site.