The situation is as follows:
At a semiconductor laboratory in Hsinchu a security guard caught five technicians accessing a high level security area reserved for the most trusted scientists working in a new integrated circuit for an upcoming computer. However the security film is not very clear and the security team can only be sure that four out of five technicians have the access key card to enter the chipset room.
During interrogation the security team deduces that two of the technicians are lying and the other are telling the truth.
The answers given by the laboratory technicians were as follows:
Audrey: Gwendolyn does not have an access credential.
Dorothy: I was entrusted an access key.
Marina: Hannah has an access key.
Gwendolyn: Audrey is lying.
Hannah: Dorothy is telling the truth.
Based on this information, which of the technicians does not have access to the chipset room?
I'm stuck at the very beginning. All I could find is this looks like a Knights and Knaves logic problem.
Since there are five individuals the number of possible combinations would be 25=32. 32 combinations seems too big to make case-by-case a practical method.
I need help simplifying this problem to find a solution.
I'm not very knowledgeable with this type of problem. It would help me a lot to visualize what's going on if the proposed solution would include some sort of table or grid so I could identify the concluded result.