Finding Poisonous Cake - Lateral Thinking Puzzle

Lateral Thinking - Lateral thinking involves solving problems through an indirect and creative approach. It's all about using reasoning that is not immediately obvious and involving ideas that may not be obtainable by using only traditional step-by-step logic. Lateral thinking puzzles are strange situations in which you are given a little information and then have to find the explanation.

What is lateral thinking?

It essentially means being able to think creatively or "outside the box" in order to solve a problem. Usually, logical thinking is used to solve problems in a direct, straightforward way (also known as vertical thinking).

Here is an interesting lateral thinking puzzle that requires out-of-box thinking to solve.

Puzzle Details

John has three cakes. One cake is poisoned, and he knows which one. What yes/no question can you ask John to find out which cake is poisoned?

Solution

This Puzzle can have multiple interpretations.

let's make a couple of assumptions to answer this puzzle, the first one is that, we are allowed to cut the cake and the second one is that John says the truth only among the two options Yes/No.

First Interpretation So, we have three pieces of cake, say A, B, C. Let us cut the cake C into two equal portions, say C1 and C2. Now put C1 with A and C2 with B. So we have now two segments of cake pieces, viz, AC1, and BC2.

Now our question to John is: “John, is AC1 more poisonous than BC2?”

If John says Yes, that means A is poisoned. Throw it out and eat B, C1, and C2. A is poisonous because A is larger in size compared to C1. If John says No, that means two options (the first option is AC1 is less poisonous or BC2 is more poisonous, and the second option is AC1 and BC2 are equally poisonous). Here it is clear that A is not poisonous. In this case, I suggest we better don’t go for any adventures, and eat piece A, leaving B and C (C1 and C2) for John. In any case, he can’t eat both, he would eat only the pure cake, and would definitely throw away the poisonous one.

Again here there is no clear guarantee that poisonous cake is identified but at least this will provide us the logical conclusions.

Second Interpretation

let me explain another interesting interpretation, according to this interpretation, One question is sufficient to find a single non-poisonous cake but one question is insufficient to determine the poisonous cake, let A, B, and C be a labeling of the cakes. If you only have the option to ask one question and can take no other action, there is no such question. A yes-no question gives you one bit of information. You need two bits of information to distinguish the poison cake from the non-poison cakes. as I have already mentioned, One question is sufficient to find a single non-poisonous cake. Let the cakes be labeled A, B, and C.

You can then ask the question: “Is the poisonous cake either A or B?”

If the answer is yes, then you know that cake C is non-poisonous. If the answer is no, then you know both cakes A and B are non-poisonous. Note that this question is insufficient to determine the poison cake. If the answer to the question is yes, then all you know is that either A or B is poisonous, but not which one. You would need an additional question to determine that.

So, there is no single correct answer which can be the solution to this riddle. do share your answer in the comment section.

watch the below video for detailed explanation