Can you solve the private eye riddle? - Henri Picciotto
- 831,765 Views
- 741 Questions Answered
- TEDEd Animation
Let’s Begin…
Create and share a new lesson based on this one.
For example, 41 (which is already prime), or 41075 → 41|07|5. Explore slime numbers in this worksheet (It is excerpted from the materials in Henri Picciotto’s Infinity, an elective high school math course).
When thinking about whole numbers, it is convenient to quickly recognize multiples of certain numbers. (For example, all multiples of 5 end in 0 or 5.) Wikipedia has a big list of divisibility tests.
Want more puzzles? TED-Ed has lots of fun and challenging brainteasers in our Riddle Series!

Create and share a new lesson based on this one.
More from Can You Solve This Riddle?
Can you steal the most powerful wand in the wizarding world?
lesson duration 05:20
259,771 views
425,345 views
712,895 views
853,847 views