Ham Yesterday, Pork Today
When Adrian, Buford, and Carter eat out at the local Shari's every evening, each person orders either beef or pork. A history of twenty years of eating meals together warrants these conclusions:
[i] If Adrian orders beef, Buford orders pork.
[ii] Either Adrian or Carter orders beef, but not both.
[iii] Buford and Carter do not both order pork.
Who could have ordered beef yesterday, pork today? Justify with reasoning.
Source: Some recreational logic book I used more than two decades ago....
Hint: Draw diagram representing the various cases...or make an assumption, test it, modify, etc.
Solution Commentary: It must be Adrian, Buford, or Carter...hope that helps a little....that is, I know you can do this one and know you are right, without having your answer confimed by an outside authority.