Numbers from 1 to 10 are written in a row:
1 2 3 4 5 6 7 8 9 10.
Is it possible to place + and − signs between them so that we get 0?

Leaflet #parity

Parliament consists of two equal chambers. All representatives of both chambers were present at the joint meeting connected with the adoption of an important decision. Due to the importance of the issue, no one abstained from voting. After summarizing the results, it was announced that the decision was made by a majority of 25 votes. The opposition shouted: "This is a hoax!" How was this determined?

Leaflet #parity

This time Bart corrected two numbers in the multiplication example.
It turned out 4 · 5 · 4 · 5 · 4 = 2247. Help teacher Ms Clayton restore the original example. (Determine which numbers were corrected for what, and explain why it could not have been done otherwise.)

Leaflet #parity

🗣 Share the problem with friends!
💬 Write comments!
☀️ Have a great weekend!

Three jars labeled "raspberry", "strawberry" and "raspberry or strawberry" were filled with currant, raspberry and strawberry jam. All labels were incorrect. What kind of jam was poured into the "strawberry" jar?

Leaflet #logic

"Pure mathematics is in its way, the poetry of logical ideas." - Albert Einstein.

#quote

When the teacher scolded Sheldon for bad handwriting, he said: "All great people had bad handwriting, so I'm a great person."
Is he right?

Leaflet #logic

Peppers were stolen from the president. As you know, those who steal pepper always lie. The press secretary said he knew who stole the pepper. Is he guilty?

Check the answer here

Leaflet #logic

Among four people, there are no three with the same name, or with the same patronymic, or with the same surname, but every two have the same name, or surname, or patronymic. Could this be?

Check the answer here

Leaflet #logic

Someone gave Winnie-the-Pooh a barrel of honey, placing it on the porch of his house. Pooh suspects that it was one of his friends: Piglet, Tigger or Eeyore. But how do you know? Each of them points to one of the other two. Only Piglet told the truth. If everyone pointed not to the one they point to, but to the second one, then Eeyore would be the only one who told the truth. Who gave the gift?

Leaflet #logic

One of the three friends gave honey to Rabbit in the same way. Piglet answered Rabbit's questions that it was Eeyore, and Rabbit forgot what Eeyore and Tigger said. Pooh took matters into his own hands and found out that only one of the three had told the truth, and he was the one who made the gift. Who gave the gift?

Leaflet #logic

Today, July 22, is Pi Approximation Day!

#celebration 🎉

Cowboy Joe bought several bottles of Coca-Cola for 40 cents each, several sandwiches for 24 cents and 2 steaks at the saloon. The bartender said it was $20.50. Cowboy Joe told the bartender everything he thought about his ability to count. Was the bartender really wrong?

Leaflet #logic

Three clown brothers Paul, François and Albert from the Fratellini family entered the arena wearing red, blue and green shirts. Their shoes were the same three colors. François's shoes and shirt were the same color. There was nothing red on Albert. Paul's shoes were green, but the shirt was not. What color shoes and shirt did Albert and François have?

Leaflet #logic

There are only two dollars in two wallets. At the same time, there is twice as much money in one wallet as in the other. How can this be?

Leaflet #difficult_situation

🗣 Share the problem with kids!
💬 Write comments!
☀️ Have a nice Sunday!

The castle is surrounded by a moat shaped like a rectangular frame. The width of the moat is the same everywhere. There are two boards whose lengths are equal to the width of the moat. Is it possible to cross the moat?

Leaflet #difficult_situation

Is it possible to load seven barrels of lemonade, seven empty barrels and seven half-filled barrels onto three trucks so that each truck has seven barrels and an equal amount of lemonade?

Leaflet #difficult_situation

Two trains are moving towards each other on the same railway line. A dead end departs from it, the length of which is less than the length of the train, but more than the length of one car. How do trains miss each other?

Leaflet #difficult_situation

Three kittens and three puppies ate twenty sausages. The red kitten ate the most, and the gray one ate the least. Could it be that the puppies ate no less sausages than the kittens?

Leaflet #difficult_situation

🎞 The Futurama Theorem

There are at least ten liters of water in the tank. Is it possible to collect six liters with a nine-liter bucket and a five-liter can?

Leaflet #difficult_situation

🎞 9.999... really is equal to 10

A peasant needs to ferry a wolf, a goat and cabbage across the river. But the boat is such that only a peasant can fit in it, and with him either only a wolf, or only a goat, or only cabbage. But if you leave a wolf with a goat without a peasant, then the wolf will eat a goat, if you leave a goat with cabbage, then the goat will eat cabbage. What to do?

Leaflet #difficult_situation

More about this river crossing puzzle

A woman picked apples in the garden. To get out of the garden, she had to go through four doors, each of which was guarded by a fierce guard who took away half of the apples. She brought home 10 apples. How many apples did the guards get?

Leaflet #reverse_course

📑 Science or prayer?

An alley of trees was planted in a row in the park. A year later, another one was planted between any two neighboring trees. A year later they did the same. There were 1197 trees. How many were there initially?

Leaflet #reverse_course

🎞 The Unbeatable Game from the 60s: Dr NIM

Two pirates were playing for gold coins. First, the first lost half of his coins and gave them to the second, then the second lost half of his coins to the first, then again the first lost half of the coins. As a result, the first turned out to have 15 coins, and the second 33. How many coins did each of the pirates have before the game started?

Leaflet #reverse_course