6 AM Quiz: Let's Test FIDO out!

In this round of 6 am quiz, you will attempt to uncover the mystery behind Fido's Mind-Reading ability.

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Fido claims that he can read our mind.
Click at the following link to test him out!!! :
http://www.digicc.com/fido/

There are several ways to explain Fido's trick, using mathematical reasoning. 

Make an attempt to use ALGEBRA to explain the "trick"?

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Enter your thinking (algorithm) in Comments.

6 AM Quiz: Bridge Crossing

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The 6 AM Quiz is a platform to engage those who would like to seek deeper exploration and understanding of selected topics. It is therefore not compulsory.

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Solve your puzzle and present the possible solution in the Comments
While you tried to solve the puzzle, what mathematical knowledge and skills did you apply to solve the problem?