# Helping a team guess a correct number without prior knowledge [duplicate]

I am new here and would like to request your explanation for a riddle I saw. It is quite interesting but I don't understand it and would like your assistance to understand what's going on, how to "guess" the number and what the strategy needs to be.

Here's the riddle:

A team of football players, consists of 100 players, are put in their own respective rooms after a failed football game. Each of them are assigned a number, from 1 to 100, that they don't know (the number can repeat itself, meaning two players can have the same number, and some numbers might not occur).

To avoid being locked in their rooms, A player(at least one player out of the 100), needs to correctly guess his assigned number. If even one player got it right, they can exit their rooms.

They cannot communicate with each other.

Now here are the weird parts that I don't understand:

1. To help them with this difficult task, before being put into their rooms, they were allowed to try and devise a strategy to get at least one player get a correct guess.
2. After each player being put into his respective room, they were given a list of the assigned numbers (meaning the "answer")

I really don't understand how this information can be utilized in order to understand how to guess a number correctly, to help them get out of their rooms. Again, only one correct guess is needed.

Please try to explain simply to help me understand it, as I am really intrigued but I do lack the proper skills to understand it properly.

Busting my head on it for a few days and finally surrendered

• Welcome to Puzzling.SE! This looks like one of the many variants of this puzzle; take a look and see whether the solution presented there helps you out at all. If it does, we can close this as a duplicate; if it doesn't, please edit your question to explain why. Dec 12, 2020 at 14:35
• puzzling.stackexchange.com/questions/105567/… Dec 12, 2020 at 15:40
• Are they given the whole of the list , is your question different from the above?? Dec 12, 2020 at 15:45
• Thank you very much, The link and the references helped in understanding the reason behind the modulo n. It can be closed and thank you again for helping me Dec 12, 2020 at 17:49
• Hi, welcome to PSE! I don't understand what point 2. means ([the players] were given a list of the assigned numbers) Dec 12, 2020 at 18:57