let's do puzzles: logic game #17

Four students-Willam, Xi, Ybarra, and Zoe-cooperate by each typing the lecture notes for the two classes they all share-Anthropology and Biology. Each student types the notes for exactly two class meetings a week. Each class meets once per Monday, Tuesday, Wednesday, and Thursday. The typing of the notes conforms to the following conditions:




A student may type notes for only one class a day.

Xi and Ybarra do not type notes for classes that meet on the same day.

Zoe does not type notes for Anthropology classes.

Williams does not type notes for classes that meet on Thursday.




SOLUTION:

B.                  z

A.                 X/y ~Z

      M. T. W. Th

                   ~W

NOTE: the game proved to be easy even though the setup was not  recorded in my mind right away. The inferences from the general sketch were crucial. Otherwise, if you do not register the inferences right away, then jump right from the first acceptability question, then, to detail "if" scenarios questions.