How does the brain teaser that answers red hammer work?

The math sequence of question is needed to keep the associative part of your brain inactive, then suddenly you are asked to name a tool and a color. By culture the majority of people has a subconscious knowledge that associates a hammer to the concept of tool, and red to the concept of color. A very simple answer to a shocking test! We are all the same, after all! Note that this test works in any language where culturally those items are the predominant for those concepts (a lumberjack or a farmer may not answer "hammer" as they are more exposed to different tools).