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3 logical tasks that only the smartest can solve
3 logical tasks that only the smartest can solve
Anonim

Try to escape the evil zombies, deal with the messed up boxes, decipher the secret code and save the world.

3 logical tasks that only the smartest can solve
3 logical tasks that only the smartest can solve

1. Escape from evil zombies

The grief student arrived for an internship at an abandoned laboratory on the hill. On the very first day, out of curiosity, he pulled the lever on which a skull was drawn and released a squad of evil zombies. There is no time to think: you need to get away from them and as soon as possible.

A watchman, a laboratory assistant and an old professor run along with the student. They broke away from the pursuit, but there is only one way to salvation - an old rope bridge thrown over an endless abyss. A student can cross a bridge in 1 minute, a laboratory assistant in 2 minutes. The watchman will need 5 minutes, and the professor - as much as 10.

Logic puzzle about zombies
Logic puzzle about zombies

According to the professor's calculations, the zombies will overtake the fugitives in 17 minutes. This is exactly how much time the group has to cross the chasm and cut the bridge. The matter is aggravated by the fact that it is dark around, and the old lamp, which the student has taken, barely shines.

Can you figure out how to get the student, professor, technician, and watchman to the other side of the bridge before being devoured by the evil zombies?

Just remember this:

  1. Only two people can be on the bridge at a time.
  2. One of those crossing the bridge must have a lamp in his hand, others can wait in the dark on either side of the abyss.
  3. You need to meet in 17 minutes, otherwise the first zombie can step on the bridge while there are still people there.
  4. Cheating is useless: you cannot jump over the abyss on a rope, you cannot use the bridge as a raft, make friends with zombies or come up with something else.

1. Student and laboratory assistant go to the safe side together. This takes 2 minutes.

2. A student with a flashlight single-handedly runs over to the side of the laboratory. It takes another 1 minute, only 3 have passed.

3. The student gives the flashlight to the watchman and the professor, they go over to the safe side. It takes 10 minutes, in total 13 minutes have passed.

4. The laboratory assistant grabs the flashlight from the watchman, returns to the side where the student was left. It takes 2 minutes, 15 minutes have passed.

5. The laboratory assistant with the student go to the safe side. It takes 2 minutes, 17 in total.

Hurray, everyone is saved! At the very last moment, the student cuts the pillars of the rope bridge, leaving the zombies with nothing. Ha ha!

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2. Secret password

The world is enslaved. The resistance squad is the last hope of humanity. But here's the bad luck: the despotic rulers seized the brave trinity and sent them into captivity.

Before they were thrown into the dungeon, the guys saw many numbered corridors leading to freedom. But every exit was blocked by an electrical barrier. To disable it, you need to enter a special code.

Logic problem about the secret code
Logic problem about the secret code

One of the members of the squad is ready to release if he can pass the test, and the rest will be fed to mutant salamanders the next morning. The guys choose Zoya with her excellent logical thinking and equip their friend with a transmitter to hear everything that happens to her.

When Zoya is taken away, the squad members hear an echo of her footsteps in one of the corridors, then the sound is cut off. Someone's voice announces that she needs to enter a code of three positive integers in ascending order so that the second number is greater than or equal to the first, and the third is greater than or equal to the second. The girl has three clues, and if she does not guess the code or says something else, she will again go to the dungeon.

Logic problem about the secret code
Logic problem about the secret code

“The first clue,” the voice says, “the product of three numbers in the code is 36”. When Zoya asks for a second clue, the voice says that the sum of these numbers is equal to the number of the corridor through which she entered.

There is a long silence. The guys in the dungeon are sure that Zoya remembers the number of the corridor, but they themselves cannot know it, and she cannot say it out loud. If Zoya could already enter the code, she would have done so, but instead the girl asks for a third hint.

The voice announces that the highest number appears in the combination only once. Soon the hum of the electric barrier stops briefly - this is how the captives understand that Zoe is free. Unfortunately, her transmitter is out of range, so this is all the information they know.

What code do the guys need to enter to escape?

The first hint indicates that we need to calculate all eight possible combinations, of which we multiply 36. One of them will be correct, but it is not yet clear which one. These are the combinations:

possible combinations according to the first condition of the logical problem
possible combinations according to the first condition of the logical problem

We do not know the number of the corridor, so we use the second hint and calculate the sum of the numbers of each combination. Here's what happens:

sums of numbers by the second condition of a logical problem
sums of numbers by the second condition of a logical problem

All but two amounts are unique. If the number of the corridor coincided with one of them, Zoe would not have asked for a third clue. Since she needed a hint, the corridor number must match the only sum that appears twice in the list - 13.

Which of the sums is correct: 1 + 6 + 6 = 13 or 2 + 2 + 9 = 13? Here the third clue will help: "The largest number occurs in a combination only once." This means that the correct code is 2, 2, 9. With its help, the prisoners will be able to get out of the dungeon at night, meet with Zoya and save the rest of the world.

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3. Parcels for the rebels

Maria is responsible for supplying important resources to the rebel base, which is located in the heart of enemy territory. At customs, all parcels are checked according to a clear protocol: if there is an even number on the bottom of the box, it must be sealed with a red lid.

A batch of boxes had already begun to be loaded into the transport when Maria received an urgent message: one of the four boxes was marked incorrectly, but which one is unknown.

The boxes are still on the conveyor belt. Two are upside down: one has the number 4, the second has the number 7. The other two boxes are upside down: one has a black lid, the other has a red one.

logic problem about parcels
logic problem about parcels

Maria knows that any violation of protocol will confiscate the consignment, and her allies will be in mortal danger. Taking the box for inspection, the girl will no longer be able to return it to the conveyor and will deprive the rebels of a vital supply. Transport is leaving soon - with or without cargo.

Which box or boxes do you need to remove from the conveyor belt?

At first it seems like you need to check the back of each box, but in reality Maria only needs two.

To understand what the solution is, let's go back to the protocol. It says that even-numbered boxes should have a red lid. Not a word is said about boxes with odd numbers, so we skip the box with the number 7.

But what about the box with the red lid? Shouldn't you check the number on her bottom? It turns out that no. According to the protocol, boxes with even numbers on the bottom should have a red lid. This does not mean that only boxes with an even number can have a red lid, or that boxes with a red lid are necessarily marked with an even number. The requirement here is one-sided, so there is no need to check the box with the red lid.

However, you need to check the box with the black lid to make sure that the box with an even number has not been accidentally covered. This means that Maria needs to remove two boxes from the conveyor: the one with the number 4 written on it, and the one with a black lid.

If you thought that red lids could only be on even-numbered boxes, you are not alone. This misconception occurs so often that it even received the name "error of the statement of the investigation."

Its essence is as follows: a certain condition is not only necessary for a specific result, but also sufficient. For example, the presence of an atmosphere is necessary for a planet to be habitable. But this condition is not sufficient. For example, Venus has an atmosphere, but that doesn't make it habitable.

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