I've seen the "find x" one. I thought it was hilarious so I showed it to some people. There was another that I believe was a physics question. I don't remember exactly what it showed but I think it was a ramp and it asked something like "does the object have enough momentum to make it up the ramp?" or something like that. The person drew an elephant in front of the ramp and answered "no, there is an elephant in the way".
