What are the drawer problems e.g. how do you put three apples into four drawers? ）？

1. There are 13 passengers in a tour group, so at least one of these travelers has the same zodiac sign.

2. In the fifth grade, 47 students participated in a mathematics competition, and the results were all whole numbers, and the full score was 100 points. Three students were known to have scores below 60 points, while the rest of the students were all between 75 and 95 points, and at least one student had the same score.

3. 11 points on any point on the line segment with a length of 2 meters, and the distance between at least one point is not more than 20 centimeters.

4. There are 5 children, and each of them pulls out 3 chess pieces from a cloth bag containing many black and white chess pieces. Please prove that at least two of the five children have the same color matching of the chess pieces.

5. Divide 125 books to five (2) classes, if at least 1 of them is assigned 4 books, then the class has the most.

6. Teacher Yu of Class 5 (1) gave two questions in a mathematics class, stipulating that each question is worth 2 points if you do it correctly, 1 point if you don't do it, and 0 points if you do it wrong. Teacher Zhang said that if there are at least 6 students in the class who have the same score on each question, then there will be at least one person in the class.

7. From the starting point, plant a tree every 1 meter, if you hang three or two small wooden signs of "caring for trees" on the three trees, then no matter how you hang them, there are at least two trees that are listed, and the distance between them is an even number (in meters), why is this?

8. Some children are playing on the beach, they pile up many piles of stones, and one of them found that five piles were randomly selected from the pile of stones, and at least two of them were separated by multiples of 4, do you think his conclusion is correct? Why?

2. Extracurricular development.

1. There are 80 red balls, 70 blue balls, and 50 white balls in the bag, they are the same size and quality, and 10 pairs of balls should be guaranteed to be touched (two balls of the same color are 1 pair), at least how many balls should be taken?

2. From 1, 2, 3, 4 ,..., 19, 20 of the 20 natural numbers, at least any ( ) number, you can ensure that there must be two numbers, and their difference is 12.

3. Proof that any 10 points in an equilateral triangle with an edge length of 1 must have two points, and the distance between them should not exceed 1 3.

4. The relationship between students who graduated from the same primary school can be divided into three levels: close relationship, general relationship, and no relationship. Well, among the 17 alumni of this school, there are at least ( ) individuals, and their relationship is on the same level.

How many of the 13 people have the same zodiac sign?

Analysis: Put 3 apples into 3 drawers, at least 3 3 = 1 (pieces), that is, at least one drawer should be placed at least 1; Put 4 apples in 3 drawers, 4 3 = 1 (pcs)....1, that is, after putting 1 in each drawer on average, there is still 1 left, so at least one drawer should be placed at least 1+1=2.

5 4 = 1 pc....1, 1+1=2 (pcs), that is, there is always a drawer with at least 2 apples wide

So the answer is: Judgment.

Summary. Put four apples into three drawers, the first apple has 3 ways to put it, the second one has 3 drawers to choose from, and the third one is.

So it adds up to 3*3*3*3, which is 81 methods.

With three drawers, four apples, how many different ways are there? (Repeatable, to**) put four apples into three vertical drawers, the first apple has 3 ways to put Jichang, the second also has 3 drawers can be selected at will, and the third is still so it adds up to 3 * 3 * 3 * 3 is 81 methods.

Hope my answer helps you, thanks.

There is no understanding. There are three choices for each apple, so 3*3*3*3=81 is not understood. There are three options for each apple, so 3*3*3*3=81 is not either.

Correct, assuming that there are only two apples in each drawer at most, then there are only 6 apples at most, and there are eight apples in the question, so there is at least one drawer with three or more apples.

Same upstairs: Counter-evidence is sufficient.

The hypothetical argument does not hold water.

Then: Put ten apples in four drawers, there must be no three apples in the same drawer, then: each drawer has a maximum of 2 apples.

Because: the number of drawers is 4, and two are placed in each drawer.

So: all drawers are full as 4*2=8

8 is less than 10, does not meet the assumption that all 10 apples are put into 4 drawers, and is not true.

So there must be only one drawer missing for 3 or more.

That's pretty much it.

Take the median hypothesis.

If you put 2 apples in each drawer, you will have a total of 8 in 4 drawers, and there will be 2 unplaced, so any drawer can meet the conditions.

98 8 = 12 (pcs).2

Put at least 12 apples.