Gamestar Forum

I forget the formula for these problems, but just going by logic...43, I think?

What is wrong with this proof?
"The method of induction states that, if f(1) behaves how we like, and f(n+1) behaves how we like as long as f(n) does, then f(n) always behaves how we like. This is also referred to as the "domino effect:" if the first domino falls, and if each domino can be knocked by the one before it, all the dominoes will be knocked over. I will use this to prove that all horses are the same color.

Suppose you have 1 horse. It is the same color as itself, so the property works for a single horse.

Now suppose the property works for any group of n horses. For any arbitrary group of n+1 horses, #1 through #n are all the same color, and #2 through #n+1 are all the same color, so all n+1 horses are the same color. By induction, all horses are the same color. Q.E.D."

(I first heard this riddle from The Art Of Problem Solving)

Invalid riddle. The answer is not a "Who", it is a "What". Foul Play.

Here's my attempt at making a knights-and-knaves riddle:

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You meet four amateur riddle-tellers; Alex, Barbara, Carl and Dave; who ask you to solve a riddle.

"Two of us tell the truth, but two of us are liars..." says Alice.

"No, that's not right--one of us tells the truth, and three lie," says Barbara.

"What? But Alex never said that we had fewer than two truth-tellers," says Carl.

"Could you help us out?" Dave asks you. "How many of us are liars in this riddle?"

"No need," you respond, "I already know which of you are lying and which of you are truthful."

Who are the liars?