The Prompt（习题2）

问题

• Cathy has two unknown 3's in her hand.
• What are the two possible clues that Alice can give?
• Which one is better and why?

题解

• First, Alice can clue yellow to Bob:
  • This would be a Play Clue on the yellow 4, which would Prompt Cathy.
  • Cathy would play her left-most 3 and then stop.
• Second, Alice can also clue blue to Bob:
  • This would be a Play Clue on the blue 4, which would Prompt Cathy.
  • Cathy would try to play blue 3 from slot 3. However, it would be yellow 3, which would successfully play.
  • Cathy would know that she is promised to have the blue 3, so she would go on to play her other 3 as the blue 3.
• The second clue is better than the first clue because it gets Cathy to play two cards instead of one.