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Error in python book?

  1. Jul 5, 2008 #1
    In python for the absolute beginner, we have this (page 28):

    "If an alien has 3 heads, grows 1 more than double his total number of
    heads, how many heads does the alien have?"

    My formula is: (3 * 2) + 1

    (For example, in this sequence, each sequential number is one more than double the next one: 2, 5, 11, 23, 47.)

    but he gives (3 + 1) * 2 = 8. But he says one more than double his (current) total. So that seems incorrect.

    Who is right?
     
  2. jcsd
  3. Jul 5, 2008 #2

    CRGreathouse

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    I would have thought

    3 + (3*2 + 1) = 10

    heads.
     
  4. Jul 5, 2008 #3
    Yes. That's right. The error was my own. It says "if an alien has 3 heads, grows 1 more THEN doubleS his total number of heads, how many heads does the alien have."

    In fairness, I couldn't really see. That part of the program is only in the console window, not in the source code he gives (for some reason).
     
  5. Jul 5, 2008 #4
    Maybe it's meant to say:
    "If an alien has 3 heads, grows 1 more then doubles his total number of heads, how many heads does the alien have?"

    It's awkwardly-phrased as it is.
     
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