How to approach this problem: "You run a boarding house with 90 rooms..."

jgraham1997

New member
Joined
Aug 9, 2017
Messages
2
You run a boarding house with 90 rooms. You have 100 regular guests. On anygiven night a random selection of exactly 90 of your regular guests will show up, each needing a single room.You want to distribute a set of keys to the guests permanently in such a way that no matter which 90 guestsshow up on a given night each one will be guaranteed access to a room. (One way to do this would be togive each of the 100 guests a key to each of the 90 rooms, but that would require you to distribute 9000keys.) What is the minimum number of keys you must distribute?
 
You run a boarding house with 90 rooms. You have 100 regular guests. On anygiven night a random selection of exactly 90 of your regular guests will show up, each needing a single room.You want to distribute a set of keys to the guests permanently in such a way that no matter which 90 guestsshow up on a given night each one will be guaranteed access to a room. (One way to do this would be togive each of the 100 guests a key to each of the 90 rooms, but that would require you to distribute 9000keys.) What is the minimum number of keys you must distribute?
What are your thoughts?

Please share your work with us ...even if you know it is wrong.

If you are stuck at the beginning tell us and we'll start with the definitions.

You need to read the rules of this forum. Please read the post titled "Read before Posting" at the following URL:

http://www.freemathhelp.com/forum/announcement.php?f=33
 
I unsure of where to begin to tackle the problem so have not got any work to post

I have considered some systematic distribution of the keys, but am unsure on how I am supposed to arrive at a value for the minimum numbers of keys to ensure every person has a room.
 
Last edited by a moderator:
I unsure of where to begin to tackle the problem so have not got any work to post

I have considered some systematic distribution of the keys, but am unsure on how I am supposed to arrive at a value for the minimum numbers of keys to ensure every person has a room.
Maybe start from the number of keys you'll need on any given night.... (explained here) ;)
 
Top