Challenge Questions Blog

Challenge Questions

Stop in and exercise your brain. Talk about this month's Challenge from Specs & Techs or similar puzzles.

So do you have a Challenge Question that could stump the community? Then submit the question with the "correct" answer and we'll post it. If it's really good, we may even roll it up to Specs & Techs. You'll be famous!

Answers to Challenge Questions appear by the last Tuesday of the month.

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The Line Illusion (September 2026 Challenge Question)

Posted August 31, 2026 12:00 AM
Pathfinder Tags: challenge question

How many lines are there in these pictures? Explain the phenomenon depicted. (Apologies for the freehand Sharpie!)

Figure 1

Figure 2

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Previous in Blog: Chess Test (August 2026 Challenge Question)  

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