Think You’re Smart? Prove It with This Jelly Bean Brain Teaser

You have three jars, each labeled incorrectly:

1. Jar 1: Labeled “Red Jelly Beans”
2. Jar 2: Labeled “Blue Jelly Beans”
3. Jar 3: Labeled “Mixed Jelly Beans”

Each jar actually contains one of the following:

• Only red jelly beans.
• Only blue jelly beans.
• A mix of red and blue jelly beans.

Challenge:

Since all the labels are wrong, how many minimum jelly beans would you need to pull out to correctly identify what is in each jar and fix the labels?

 

 

 

 

 

 

 

 

The Trick:

The key is to realize that all the jars are mislabeled. None of the jars contain what their label says.

So, for example:

• The jar labeled “Mixed Jelly Beans” (Jar C) cannot actually be the mix—it must contain only red jelly beans or only blue jelly beans.

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The Solution:

To solve the puzzle, you pick one jelly bean from the jar labeled “Mixed Jelly Beans” (Jar C). This jar is your best option because its label guarantees it does not contain a mix.

1. If you pick a red jelly bean from Jar C:

   • Jar C must contain only red jelly beans (because it’s mislabeled and cannot be mixed).

   Now you know the other jars:

   • The jar labeled “Blue Jelly Beans” (Jar B) cannot actually contain only blue jelly beans, and it also cannot contain only red jelly beans (that’s Jar C). So, it must contain the mixed jelly beans.
   • That leaves Jar A (labeled “Red Jelly Beans”) to contain only blue jelly beans.

2. If you pick a blue jelly bean from Jar C:

   • Jar C must contain only blue jelly beans.

   Now you know the other jars:

   • The jar labeled “Red Jelly Beans” (Jar A) cannot actually contain only red jelly beans, and it also cannot contain only blue jelly beans (that’s Jar C). So, it must contain the mixed jelly beans.
   • That leaves Jar B (labeled “Blue Jelly Beans”) to contain only red jelly beans.

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Final Answer:

By picking one jelly bean from the jar labeled “Mixed Jelly Beans,” you can correctly relabel all the jars:

• If Jar C is red:

  • Jar A: Blue jelly beans.
  • Jar B: Mixed jelly beans.
  • Jar C: Red jelly beans.

• If Jar C is blue:

  • Jar A: Mixed jelly beans.
  • Jar B: Red jelly beans.
  • Jar C: Blue jelly beans.

The minimum number of jelly beans you need to pick to solve the puzzle is 1.