I've seen a few variations on that one, but they are all based on the question "name a country starting with the letter D" because there are only 4 apparently, and nearly everyone will say "Denmark". For example...
Name a country starting with D
Take the last letter of that country and think of an animal that starts with that letter
Take the last letter of the animal and think of a colour....
(the answer is further down the page)
I think the "red hammer" one was good because it was so unexpected - I had never seen that before and thought the test was all about mental arithmetic. I guess it's the same with a lot of "magic" tricks - the magician distracts your attention, or makes you concentrate on something to distract you while he does what he has to do.
I'll bet you said Denmark, Kangaroo and Orange