The five students chose one of the three tourist spots to travel, and there were several different w

There are five people, and then each person has three ideas, multiplied by five, not 15

You can try the numerical method in mathematics.

Choose 2 attractions from 3 attractions to play, there are 3 ways to play, 3x4+1=13

Three attractions are drawers, 4 is at least counted. 4 minus 1 equals 3 and is the average number of each drawer.

3 times 3 plus 1 equals 10 people. There are 10 people.

That's the question you're asking

A few close friends went to the three attractions of ABC, and each person only visited two of them, and no matter how they arranged, at least 4 people visited the exact same attraction. Please ask at least a few people to go.

Answer: At least 5 people.

1st person: ab

2nd person: AC

3rd person: BC

Each appears twice, and as long as two people are added, no matter which two attractions these two people visit, they will visit the same one, so that there can be four people visiting the exact same attraction.

The topic is unclear = = ask for addition.

It's not clear, who can say it better.

Each group has 3 options, a total of 3*3*3*3=81 types.

It's 3 4 because it's a group and each group chooses a scenic spot, so you have to choose four times, and there are three possibilities each time

Of course, if there are other requirements, you can consider covering oranges separately, such as adding that each scenic area can only be two groups at most, so that the collapse will be solved by the permutation and combination formula

Different selection methods mean that 3 classes cannot choose the same place, so 4*3*2=24

Four tour groups choose four attractions to visit, and one of them does not have a tour group, which means that two groups must visit the same scenic spot, that is, 4 people must choose 3 attractions to visit. Then C14C24A33 = 144 kinds (C14 means that one of the 4 scenic spots is not to go, C24 means that the two groups are together, and A33 means the whole row.)

36 situations.

The tour group is ABCD, and the attraction is 1234

First of all, any of the four attractions may not be visited. That is, there are 4 cases.

Suppose attraction 1 is not visited. Then, tour group A may go to attraction 2 or go to 3 or 4, there are 3 situations. There are also 3 types of BCD groups. There are 9 cases in total.

4*9=36 cases.

There are a total of 4 classes, each class only Duanyuan chooses a tour from the 3 scenic spots of Burning Skin, each class has 3 choices, and there are 34 different options

So the answer is: 81