Brain teaser Qn over the CNY weekend.

Here is a brain teaser question over the weekend.

There are two treasure boxes. One box contains cookies and the another a gold bar. You don't know which treasure box contains the gold bar and your purpose is to obtain the gold bar. Here are the two ladies who can aid you in your conquest. They know which treasure boxes contain the cookies and the gold bar. However, there is one problem. One lady will always tell lies whenever you pose a question to her and the another will always tell the truth.
You are allowed only a question to be asked to one of the ladies. What question will you ask so that you can be 100% sure that the treasure box contains a gold bar? For your info, you also don't know which lady will always tell lies and which lady will always tell the truth?

The new module that I have picked up is quite interesting. It is related to mathematics, study of number patterns, logical deduction and reasoning using mathematics and of course common sense. The module is called Living with Mathematics and I wouldn't have expected that mathematics can be applied into logical deduction and reasoning and about the formation of strong or weak agruments. This module shows several situations where strong arguments doesn't mean that the thing that one argue for is correct.