I have watched a few American Versions of the show, and find the questions pretty easy to answer, but interestingly, I have missed a few of the 90 , 80 and 70% questions, and I feel strongly that it boils down to what a person "sees" when the question is posed.
I've answered most of the questions in the show correctly overall. ON the 1% question, I've been right 2 times and wrong 2 times, and both of the times I was wrong, I figured out the writers' intent, but could NOT answer in time. That's frustrating because 30 seconds is NOT a lot of time to digest the meaning of the question, and then analyze, and finally to get it down in writing.
I read recently that they actually get about a minute to answer when taping the show, and THAT makes a lot of sense, because this host, Patton is yapping virtually the whole time that the contenstants are trying to figure out the answer(s).
Many of the questions are word tricks or number tricks, and if you cannot figure out the writers' intent, you will fail the answer, which IMHO does NOT offer a true reflection of one's IQ or overall intelligence. The show advertises that EVERYONE is equal on the show, and that they don't need training or education but clearly there are questions that require Math Skills or Verbal and Spelling Skills or you will FAIL the questions.
It's somewhat entertaining, but I do not feel it's a good measure of how smart someone is, and more about ability to see patterns, or through what the show's writers are trying to get you to "see".