#### wubie

**[SOLVED] Error Detection**

Hello,

I have a question about error detection.

Senario:

One person can see two coins. Each coin could be laying heads up or tails up. You cannot see the coins.

Question:

What is the minimum number of questions with a "yes" or "no" response need to determine the status of two coins (that is whether they lie heads up or tails up) if two lies are permitted. All questions are tabled before any answers are given, and no hypothetical questions are allowed.

I quickly came up with one way of determining the status of the two coins:

Ask this question FIVE times about the first coin:

"Is the first coin heads up?"

Then ask this question FIVE times about the second coin:

"Is the second coin tails up?"

By taking a majority decision, one could deduce the status of the two coins. But is there a better way?

In class we have been talking about Hamming Distances. But I can't figure out how I would set this question up with regards to Hamming Distance.

Any help is appreciated.