Can you solve the Leonardo da Vinci riddle? - Tanya Khovanova

You’ve found Leonardo da Vinci’s secret vault, secured by a series of combination locks. Fortunately, your treasure map has three codes: 1210, 3211000, and… hmm. The last one appears to be missing. Can you figure out the last number and open the vault? Tanya Khovanova shows how.

Lesson by Tanya Khovanova, directed by Artrake Studio.

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[PowahSlapEntertainmint]

Too complicated, I'm bombing the door.

[mariodimov]

I solved the riddle for about 2-3 minutes on my own, after I watched the explanation I was confused for about an hour

[falthought]

Remember guys, 2020 is an autobiographical number.

[avishekchatterjee]

A rare riddle from TED-Ed where the solution is easier to get by trial-and-error than to understand the "explanation".

[katanaquits]

I don’t understand anything but his voice is smart and soothing

[breestakebobba]

Riddles: Who was the murderer?


TED-Ed Riddles: *laughs in planck's constant*

[linnmj]

"It would take forever."
I literally just started trying combinations starting with and found the answer in less time than it took to explain the calculated answer.

[Ethan-czxq]

I finally answered a riddle correctly! Although, I actually used a different method. Here's how I did it:
I decided that the simplest way of finding the number was to first consider the amount of zeros.
First possibility: there are 10 zeros. This is impossible since that would require a 10 as the first digit.
Second possibility: there are 9 zeros. This solves the problem of there being no room for the zero counter, allowing for 9 zeros and a 9 as the first digit to count the zero. However, this would require a 1 as the 10th digit, which is impossible since this would give 11 digits
Third possibility: there are 8 zeros. This solves the problem of there being no room to count the zero counting digit, giving However, there is a new problem: there is no way to count the ones, so this too is impossible
Fourth possibility: there are 7 zeros. This solves the problem of there being no way to count the ones, allowing for However, this then causes a paradox: if there is a 1 as the second digit, then there are two ones and you need a 2 as the second digit, and if there is a 2 as the second digit, then there is one one and you need a 1 as the second digit. There is a solution though: This gives you two ones and one two. One two and one one are already used, but you still have the one one you need to cover the one seven. However, one seven, two ones, one two, and seven zeros, giving 11 digits. Thus this is impossible
Fifth possibility: there are 6 zeros. This final possibility frees up the room needed to place the second one, giving us 6210001000. There are no contradictions inherent in this number, meaning that it is the right one

[emieloverduin]

When you got the right answer using the wrong formula

[yeomans]

Title: Can you solve....

Me: Probably not. But I'll watch the 5 minute video anyway.

[boobbe]

"This makes sense."

Alright, I'll take your word for it.

[joshuataylor]

I’ve watched so many of these math type riddles and I decided to actually sit down and try for once and I got it! Feels nice

[whedonobsessed]

".... Inside you find DaVinci's long lost autobiography"

*disappointed face*

[pixierush]

4:27 *when the teacher says the homework only has 3 questions*
4:30 *when you find out each question has 10 parts*

[jaromtoy]

"It would take too long to try all the possible combinations"

Whoops. Guess I got lucky then! Lesson learned - use EVERYTHING that you are given. Nice riddle!

[j.r.]

As TED-Ed riddles go, this one is fairly easy. I solved it using an instinctive trial-and-error method in less time than it took to watch the video. (The key insight is that there should be as many 0s as possible, to simplify the number.) Judging from the comments, many people used the same approach. Apparently no one used the "official, " pseudo-deductive method given. A TED-Ed answer should track how humans actually think, not merely set forth an algorithm that can be grasped in hindsight but that is more of a proof than a practical solution.

[Flem-tonk]

Wait, did he realize that the third code was missing, JUST when he got there?

[laralopez]

video: “trying different combinations would take forever”
me: found the answer in about 1-2 minutes by randomly plugging in numbers

[sufiyanmirza]

Everything is okay till you hear..."click on three, nothing on four" 😂😂

[gunterwakeup]

This was one of the few riddles I’ve ever figured out in this whole series :, )