[ubuntu-mono] [Bug 622197] Re: Mistake in the logic puzzle "Age"

[Launchpad Bug Tracker]

** Branch linked: lp:~ubuntu-desktop/gbrainy/ubuntu

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https://bugs.launchpad.net/bugs/622197

Title:
  Mistake in the logic puzzle "Age"

Status in “gbrainy” package in Ubuntu:
  Fix Committed

Bug description:
  Binary package hint: gbrainy

  Affected version: 1.50

  "John's age is nowadays 2 times his son's age. 18 years ago, John was
  5 times older than his son. How old is John's son nowadays?"

  Gbrainy says that correct answer is 40 (on the attached screenshot),
  but it isn't true. If nowadays John's son is 40, then John is 80 (2x).
  18 years ago John's son was 22 and John was 62 (2.8x, which is
  incorrect statement).

  Puzzle can be solved, using simple equation. Let son's age nowadays
  will be x, than John's age will be 2*x. 18 years ago: 2*x-18=5*(x-18).
  From this x=24. Nowadays, John's son is 24 and John himself is 48
  (2x), 18 years ago John's son was 6 and John was 30 (5x).

  Correct answer must be 24, not 40.