11. A lion is hidden in one of three rooms. A note on the door of room 1 reads "The lion is here". A note on the door of room 2 reads "The lion is not here". A note on the door of room 3 reads " $2+3=2 \times 3 "$. Only one of these notes is true. In which room is the lion hidden?
A In room 1 .
B In room 2 .
C In room 3 .
D It may be in any room.
E It may be in either room 1 or room 2 .
11. $\mathbf{C}$ Consider the three possible positions of the lion in turn. If the lion were in room 1 , the notes on both room 1 and room 2 would be true. Hence the lion is not in room 1 . If the lion were in room 2 , the notes on all three rooms would be false. Hence the lion is not in room 2. However, if the lion were in room 3 , the notes on room 1 and room 3 would be false but the note on room 2 would be true. Hence the lion is in room 3 .