Enigmas and puzzles

July 27, 2007

The spaceman's bar in Mos Unleikly spaceport was crowded, and it was virtually impossible to hear anything above the squawking cacophony of Aldebaranian jazz emitted by several creatures with flared snouts. But Stan Polo and Duke Slyhawker managed to find a relatively quiet booth behind an estivating Gigantomorph.

"You rescued the Princess like we planned?" Slyhawker asked.

"Well, kid… not yet. But I know where to find her. Almost." Polo gave a wry grimace. "We know she's imprisoned in the Clone Room, on the planet of Venupiter. I found the secret tunnel, but it's guarded by a disembodied head, at a place where it forks. If you guess the correct direction, the head lets you in. Get it wrong, and you're a smear on the ceiling."

"Aren't there two races of disembodied heads on Venupiter?"

"Yeah. Both look identical, but Veracitors always tell the truth—"

"And the Dissimulators always lie."

"You got it, kid. Visitors get to ask the head just one question, which it has to answer. I nearly asked 'What race are you?' but of course it would reply 'Veracitor,' which they both will, and then I'd have used up my question. So I made an excuse and left. But I can try again. All we have to do is find a question whose answer will tell us which fork to take, no matter what race the head belongs to. Then we can snaffle the Princess."

What question should Polo ask?



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The answer
Polo should ask: "If I asked a disembodied head whose race is not yours which fork leads to the Clone Room, what would it reply?" Whatever the answer, he then takes the other fork. A Veracitor will tell you the wrong fork, because that's a true report of what a Dissimulator would tell you. A Dissimulator will also tell you the wrong fork, because a Veracitor would tell you the right fork, but the Dissimulator lies about that.

The winner is Claire Choi