A theft has been committed on an establishment and the crime was committed by one of the four employees- Andy, Ben, Cal and Dan. Their statements are below. However, none of them can be depended upon to speak truthfully; each makes one true statement and one false statement, although in which order is unknown.
Andy
1. I do not trust Ben.
2. I am certainly not guilty.
Ben
1. Andy is guilty.
2. Dan did not do it.
Cal
1. I did not know that the theft had occurred
until I heard about it the day it was
discovered.
2. Ben did not do it.
Dan
1. Andy is innocent.
2. Cal did not do it.
Who committed the theft?
If Andy did it, then both of Ben's statements are true. Since one of the statements is known to be false, we can conclude that Andy did not do it.
Therefore, Dan's 1st statement is true.
Therefore, Dan's 2nd statement is false.
Therefore, Cal did it.