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?

  • GreyShuck@feddit.uk
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    9 months ago

    There were 30 sheep involved in the original transaction.

    The troll has 25.

    His sons have 2.

    The shepherds have the 3 that were returned.

    To look at it the other way, the shepherd paid a net amount of 27 sheep. The troll has 25, his sons have the other 2.

    You don’t add the 27 and the 2 - the 27 is the total of the 25 and the 2.

    • frankPodmore@slrpnk.netOP
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      9 months ago

      You don’t add the 27 and the 2 - the 27 is the total of the 25 and the 2.

      Thanks - this is the explanation that I finally understood!