Thursday, March 30, 2006

The safe sex puzzle

This problem is about safe sex and condoms that you may or may not have heard before. If you are able to find the solution(s) buy yourself a beer, otherwise try it on your other half (as a joke stupid). Let me assure you that there is indeed a (perhaps more) legitimate solution that works fine.

My soft side whispers that I am doing a social service. I strongly expect the solutions to be helpful under circumstances like the ones below. Read on.

Teaser

We have two men, two women and only TWO condoms. The objective is to find a way for SAFE sex (intercourse) between every man and woman. For example, if A, B are men and C, D are women then with TWO condoms you must ensure SAFE SEX between the pairs, (A, C), (A, D), (B, C) and (B, D).
REMEMBER only two condoms are allowed. How do you see that happening?


Appetizer

For three men and three women, with the condition of guaranteed SAFE sex (intercourse) between every man and woman, find the MINIMUM number of condoms needed. (Hint: the answer is NOT three)


Main course

For N men and N women where N is any finite number greater than or equal to two, find the minimum number of condoms to guarantee SAFE sex (intercourse) between every man and woman.


NOTE: Appetizer is a special case of the main course. Solving the appetizer might provide an insight (sic) or two on how to tackle the main course. Good luck and have fun!! Leave your thoughts and solutions in the comments.

from QbiT