The Five-Sided Pencil
- David Pullara
- Nov 7, 2021
- 1 min read
Imagine you have a five-sided pencil with “HB Pencil” written on one of its sides; the other four sides are blank.
If you were to roll this pencil on the table, what is the chance the side with the text on it ends up straight on top?
If you answered 20%, congratulations, you remember your high school probability classes.
But that's not the correct answer in this particular case.
In this particular case, the chances of HB Pencil landing at the top is 0%.
Because the pencil has an odd number of sides, which means gravity will force a flat side to the bottom and a "point" to the top.
"Theory" is best when you can apply it to the real world.
P.S. Here's a tip of the hat to Stacked Marketer for including this brainteaser in their newsletter a few weeks ago, which prompted this post.
Hello David - your post has me reach out to the pencils on my desk - one from Staedtler and another from Staples. Both have 6 flat sides ( even number) with one side
containing the brand name and HB. When I rolled both pencils there were some rolls that led to the brand being seen from a side view and other times when the brand could not be seen. I am not clear on the essence of your message. Forgive me but it may be early morning brain fog.