The Set Up:
There are three men on an island. They all have blue faces, but as far as each of them knows, his face is either blue or red, and they have made a pact that if any one of them comes to know for certain the color of his own face he will kill himself at midnight. Part of the pact is that they will not and cannot reveal to each other the color of each other’s faces, as they can see them.
Day zero: They order a pizza. The pizza man arrives and makes the statement to all three of them, but no one in particular: “At least one of you has a blue face.”
Day two: They each have discovered for certain that their face is blue.
Day three: All of them are dead.
The question: How did at least one of them come to know that their face was blue?
Important and significant parts to the riddle:
The pizza man's statement-- as it implies something an sets things off.
The time: The fact that it is by day two that they come to know the color of their faces, and they are dead on day three.
This is a straight up riddle, there are no tricks. No one looks at his face in the water or anything of that sort. Also, the set up is just a set up, the island or anything else does not factor into the answer. This is a logic riddle and requires purely logic to be solved.
I got into an argument with my professor because I didn't agree with his reasoning in solving it. But lets see what you guys come up with.
There are three men on an island. They all have blue faces, but as far as each of them knows, his face is either blue or red, and they have made a pact that if any one of them comes to know for certain the color of his own face he will kill himself at midnight. Part of the pact is that they will not and cannot reveal to each other the color of each other’s faces, as they can see them.
Day zero: They order a pizza. The pizza man arrives and makes the statement to all three of them, but no one in particular: “At least one of you has a blue face.”
Day two: They each have discovered for certain that their face is blue.
Day three: All of them are dead.
The question: How did at least one of them come to know that their face was blue?
Important and significant parts to the riddle:
The pizza man's statement-- as it implies something an sets things off.
The time: The fact that it is by day two that they come to know the color of their faces, and they are dead on day three.
This is a straight up riddle, there are no tricks. No one looks at his face in the water or anything of that sort. Also, the set up is just a set up, the island or anything else does not factor into the answer. This is a logic riddle and requires purely logic to be solved.
I got into an argument with my professor because I didn't agree with his reasoning in solving it. But lets see what you guys come up with.