Posts from Quiz

Yyyyyyyyyyyy. Hermit takes this question!

Answer: bicycle.
Comment: none of the Africans can ride a bicycle even a few meters – they all fall immediately. The priest explains that this is because they are pagans, and God grants Christians a special skill – not to fall off a bicycle. To be more convincing, the priest could ride without using his hands. The word "invent" is also a clue.
Source: Jean-Jacques Anno. Black and white in color.

Yeah, right.

Real own boy ran down a moving escalator and counted 40 steps. After that, he ran up the same escalator, but at half the speed relative to the escalator, and counted 280 steps. How many steps are in the visible part of the escalator?

Equations relating the length of the escalator to the speeds and the time it takes to traverse it.
X = (v + v_e) * t1 (downwards)
X = (v/2 - v_e) * t2 (upwards)
And for the number of steps:
40 = v * t1
280 = (v/2) * t2
The number of steps, unlike the total distance traveled on the escalator, depends only on the speed relative to the escalator. From the last equations:
t1 = 40/v
t2 = 560/v
Then X = (v + v_e) * 40/v = (v/2 - v_e) * 560/v
40v + 40v_e = 280v - 560v_e
240v = 600v_e
v = 2.5 * v_e
Okay, then:
X = 3.5 * v_e * 40 / (2.5 * v_e) = 3.5 * 16 = 56

56 steps

Ment, as always, guessed everything correctly. Go ahead and ask another riddle!

I'll post it here instead of in the general chat because it's more like a problem to solve than just random chatter. It's from a problem set for 4th grade, but I couldn't solve it in any way other than by trial and error, and it turns out there's a more elegant solution. Does anyone want to share their elegant solution?

Using the digits 4, 5, 6, 7, and 8, each only once, find the largest possible product.

_______X_X_X
_____x
__________X_X
_______________

This is a picture showing a three-digit number being multiplied by a two-digit number. Instead of X, you need to put the digits 4, 5, 6, 7, and 8.
I'm just not a very good artist.

(a*100+b*10+c)*(d*10+e)=max
a*d*1000+a*e*100+b*d*100+b*e*10+c*d*10+c*e=max
From this, it is clear that d contributes the most to the expression (multiplier 1000a+b*100+c*10), then a, then b (d*100+e*10), then e (a*100+b*10+c), and finally c.
Therefore, 764*85=64940
Is this correct?

Yes, that's correct. And your solution looks simpler and more elegant than the one in the problem book. Although, it's understandable, as fourth-graders aren't yet capable of solving such complex equations.

I'll bump the thread.
Here are some riddles for you, try to solve them:)

In principle, I understood most of it – except for the cyborg and the drug-addicted girl
(but let others struggle with it).

The cyborg also confused me, although we don't have that many cyborgs in our fairy tales who are so fond of sweets.

1) The Golden Fish
2) Thumbelina? Not sure somehow.
3) Alyonushka and Ivanushka
4) Spirited Away, or something like that? )) I also thought about the swineherd and the shepherd, but it doesn't seem to be about that.
5) I don't know. I don't remember who likes sweets in fairy tales, except for Hansel and Gretel.
6) Well, that's Pinocchio
7) Ivan Tsarevich and the Grey Wolf (there was a scene with Baba Yaga and her hut)
8) Kascha from the Axe
9) The Wolf and the Seven Kids? I think that's what it's called? Why didn't the journalists mention that these were mutant goats? )
10) The Gingerbread Man (I was waiting for him)
11) Snow White and the Seven Dwarfs. Although I initially thought of Mario.
12) Alice, is that you? (Awful journalists, but Alice isn't even a fairy tale character.)
13) The Little House
14) Beauty and the Beast
15) The Tale of the Priest and His Servant Balda
16) Hmm, the magic flower? I never thought of it as a fairy tale, but I guess it is.
17) The Nutcracker. And that's the coolest headline ))

5. Karlsson, who lives on the roof.

Ment.
4 - If I'm not mistaken, it's Andersen, or maybe Perrault, or the Brothers Grimm, "The Swineherd." There, a prince disguises himself as a swineherd, and the princess gives herself to him in exchange for gifts.
7 - This scene appears in 146% of Russian folk tales.
14 - "The Scarlet Flower," it's the same story, just viewed from a different angle + the flower does play a key role.
And fifth, Hermit told it, well done, and he didn't even spoil it.

1. The Tale of the Golden Fish. (A. Pushkin)
2. I don't know
3. I remember the tale, but I don't remember the exact title. I think it's "Sister Alenushka and Brother Ivanushka." (I don't know who wrote it.)
4. I remember the tale, but I don't remember the exact title. (I'm not sure who wrote it. Maybe Hans Christian Andersen)
6. Pinocchio. (A. Tolstoy, I think)
7. I don't know.
8. Kascha iz Topora (Porridge from an Axe). (I think it's a Russian folk tale.)
9. I don't know.
10. I don't know.
11. I don't know.
12. Alice in Wonderland.
13. The Three Little Pigs. Maybe also "The Cat's House" (S. Marshak)
14. The Scarlet Flower.
15. The Tale of the Priest and His Servant Balda. (A. Pushkin)
16. Something like "The Flower with Seven Colors."
14. The Nutcracker and the Mouse King. (I don't remember exactly. I think it's by E.T.A. Hoffmann.)