Who killed Sharky and Why?

I know it’s a strange title, but follow me just for a minute. The title is a question posed in a class I took about logic and data structures.

You are given several pieces of information in the form of statements given by four people. One of them is telling the truth while the other four are lying. Based on their statements and the use of logic, you are to figure out “Who killed Sharky and Why?”

Here’s the exact problem:

Sharky, a leader of the underworld, was killed by one of his own band of four henchmen. Detective Sharp interviewed the men and determined that all were lying except for one. He deduced who killed Sharky on the basis of the following statements:

Socko: Lefty killed Sharky

Fats: Muscles didn’t kill Sharky

Lefty: Muscles was shooting craps with Socko when Sharky was knocked off

Muscles: Lefty didn’t kill Sharky Who killed Sharky and why?

Well instead of putting you through the chapters of reading, here’s how the question is answered: If Socko is telling the truth then Fats must also be telling the truth. This is not possible since only one person is telling the truth. Therefore Socko is lying. If Socko is lying then Lefty did not kill Sharky, therefore Muscles is the one who is telling the truth. Therefore Fats is lying, and Muscles killed Sharky.

Confused? I sure was. Not to brag, but I actually managed to get this question right. It took me lots of searching on the internet. So hopefully this post helps someone who may be scouring the internet looking for the age old question of “Who killed Sharky and Why?”