I just read Dr. No by Percival Everett. It contains a maths riddle that I cannot get my head around. I tried searching online but I couldn’t find any answers.

Here’s the riddle:

There are three sheepherders who come to a bridge controlled by a troll and his two sons. He demands of them thirty sheep before they can pass. Each shepherd cuts out ten sheep from his flock and they give them to the troll. Once they have crossed, the troll decides that he should only have asked for twenty-five. He sends his sons after the men with five sheep. The sons decide to keep one sheep each and give three back to the herders. They do. Now it is the case that each shepherd has paid only nine sheep. Nine times three is twenty-seven. The trolls kept two. Twenty-seven plus two is twenty-nine. Where is the missing sheep?

Can anyone help me understand?

  • Dr. Coomer@lemmy.world
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    9 months ago

    The first give 30, but the troll gives back 5, so they keep 25 sheep. The trolls kids keep 1 sheep each, so the sheaperds only get 3 back. 30 minus 3 is 27. 9 plus 9 is 18 plus 9 is 27. The riddle lied to you.

    • shastaxc@lemm.ee
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      9 months ago

      It didn’t lie. At the end it says 27+2=29, which is true. But it’s an irrelevant fact. The answer is: there are no missing sheep.