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Logic Puzzles

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Examples

Here are a few typical logic puzzles for you to try.   Start with the first below.   Just copy out the chart on a piece of paper -you don't need any of the numbering as on the first chart (this is to help when you first try using the Logic Buff).   Then study the clues and see if you can fill in the chart with bars (X) and ticks.   Remember, if you have a tick anywhere the rest of the item lines (not the whole chart line) can be filled with bars.   Also all bars but one in an item means the last point must be a tick.   Lastly .. peruse the chart entries to see if any items can be linked (related or unrelated) through connections with other common items.   Thats the tricky part .. along with finding hidden information in the clues ..

A print version of the text below can be downloaded here. This will print nicely on 4 sheets of A4 -210x297mm with 1-inch margins all round using font Courier-New size-10.


 

===========================================================================
March -                     THE LOGIC BUFF                           - 2004
===========================================================================
                 L  O  G  I  C    P  U  Z  Z  L  E  S
                 ====================================

    Logic puzzles are a fascinating way to test ones own common sense.
Unlike crossword puzzle and quiz type passtimes, Logic puzzles need no
subject background knowledge.  Just common sense, an enquiring mind and a
sharp eye.
    Logic puzzles are available in regularly published magazines from your
local newsagent.
    You become a detective in the world that the puzzle author has provided
for you. You are given or construct a chart and have a scant set of clues.
By your own ingenuity and using the clues, you must deduce the remaining
puzzle circumstances by completing and deciphering the chart.
    The Logic Buff will be your tireless companion in the quest.
MANUAL METHOD
-------------
    First you closely peruse the clues to discover the required positive
and negative connections between the puzzle subjects (items). Then you
enter them on the chart provided. This is done by entering an 'x' where you
think there is no connection, and a tick where you think that two items are
definitely connected.  These are called negative or positive relationships.
When you get a row or column of 'x' which has only one point not marked,
you know it MUST be a tick as the two associated items must relate.   Also
if you mark in a tick for any reason you are able to complete the row and
column with 'x' as there can only be ONE tick per row/column.
    The chart is developed furthur by looking for connections definite or
not, between all items in the chart.  The way to do this is to examine two
items with a common characteristic (set), and scanning what you know
already, make a decision on how they DIRECTLY relate.  For example, if your
chart shows that 'Grant was a dentist'  and elsewhere that the 'dentist
doesn't have a boat' the fact 'Grant hasn't a boat' can be safetly assumed
and marked on the chart. Here, the common characteristic set could be
'careers' or some such.
    As the chart fills, re-read the clues to find chart points which now
become more obvious 'x's or ticks.  Don't forget that there is usually more
than one part to each clue, and that the puzzle designers love to cloak an
essential piece of information so that it isn't obvious.
    Finally, when all points on the chart are filled, the answers to the
puzzle are apparent, and you can congratulate yourself.  Amazingly some
people do these in their head WITHOUT a chart!
EXAMPLES
--------
    Following are a few puzzles for you to tackle.  Why not try to do them
manually before getting the Logic Buff to help.  It will also help you to
appreciate what the Logic Buff needs, in order to help YOU.
    The puzzles have also been included as Logic Buff files for you to make
comparisons with your own clue interpretations and rule list.  Just Recall
(filename).puz.
    Beginning with an easy one..
    In this instance you have the Set and Item numbers needed by the Logic
Buff, provided on the chart for you.  This is not the case when you get
puzzles from a magazine.  Then you will have to provide them for yourself.
This is easy, as the numbering must always be according to the same method.
(See LBMANUAL.DOC).
HAPPY FAMILIES (fairly easy)
----------------------------
    Three servicemen married three ladies and in the course of time the
couples produced three fine families.  Looking at the clues following, can
you discover which ladies were married to which servicemen, their names,
and the numbers of children in each family ?
  Here are the clues:-
  1.  Tom married Jane.
  2.  Jean and her husband had three children.
  3.  Dick was in the Air Force.
  4.  Joan was not married to the sailor.
  5.  Harry's family was smaller than the soldiers family.
      (2 clues in one).
        Set nos----       4.           3.           2.
        |              Two          Soldier      Jean
        |              |  Three     |  Sailor    |  Jane
                       |  |  Four   |  |  Airman |  |  Joan
                  item
                   nos 1  2  3      1  2  3      1  2  3
            Tom     1  .  .  .      .  .  .      .  .  .
        1.  Dick    2  .  .  .      .  .  .      .  .  .
            Harry   3  .  .  .      .  .  .      .  .  .
            Jean    1  .  .  .      .  .  .
        2.  Jane    2  .  .  .      .  .  .
            Joan    3  .  .  .      .  .  .
            Soldier 1  .  .  .
        3.  Sailor  2  .  .  .
            Airman  3  .  .  .
THE VETERINARY (average rating)
-------------------------------
    Five youngsters with their pets, are queueing to see the veterinary.
From the clues given, can you find their full names, say what pet they own
and where they are in the queue.
  Clues:
  1.  The girl whose surname is Jackson has the rabbit.
  2.  Janice is not Miss Bennett, who is just after the lad with the cavey.
  3.  The parrot is fourth to be examined, his owner is not named Merton.
  4.  Gregg's surname is Harding.
  5.  Martin is three places behind the youngster named Wilson.
  6.  Norah loves cats.
                 Wilson              Parrot              First
                 |  Harding          |  Cat              |  Second
                 |  |  Jackson       |  |  Dog           |  |  Third
                 |  |  |  Merton     |  |  |  Rabbit     |  |  |  Fourth
                 |  |  |  |  Bennett |  |  |  |  Cavey   |  |  |  |  Fifth
        Emily    .  .  .  .  .       .  .  .  .  .       .  .  .  .  .
        Norah    .  .  .  .  .       .  .  .  .  .       .  .  .  .  .
        Gregg    .  .  .  .  .       .  .  .  .  .       .  .  .  .  .
        Janice   .  .  .  .  .       .  .  .  .  .       .  .  .  .  .
        Martin   .  .  .  .  .       .  .  .  .  .       .  .  .  .  .
        First    .  .  .  .  .       .  .  .  .  .
        Second   .  .  .  .  .       .  .  .  .  .
        Third    .  .  .  .  .       .  .  .  .  .
        Fourth   .  .  .  .  .       .  .  .  .  .
        Fifth    .  .  .  .  .       .  .  .  .  .
        Parrot   .  .  .  .  .
        Cat      .  .  .  .  .
        Dog      .  .  .  .  .
        Rabbit   .  .  .  .  .
        Cavey    .  .  .  .  .
WORK WORK WORK (fairly difficult)
---------------------------------
    The five fellows in this puzzle, had to give details to an insurance
company. By considering all the clues, can you find their ages, trades, and
employment situations.
  Clues:
  1.  The plumber is older than the painter, who hasn't quit work.
  2.  Dave is younger than his mechanic brother Harry, one of whom is now
      not working.
  3.  There is a six year age difference between the painter and the man
      fired who isn't Dave.
  4.  The porter who has retired, is older than Bill, who works short time.
  5.  John the salesman is 62 and older than his brother Jack.
                 50                 Porter               Full-time
                 |  56              |  Mechanic          |  Short-time
                 |  |  60           |  |  Salesman       |  |  Quit work
                 |  |  |  62        |  |  |  Painter     |  |  |  Retired
                 |  |  |  |  66     |  |  |  |  Plumber  |  |  |  |  Fired
      Dave       .  .  .  .  .      .  .  .  .  .        .  .  .  .  .
      Jack       .  .  .  .  .      .  .  .  .  .        .  .  .  .  .
      Bill       .  .  .  .  .      .  .  .  .  .        .  .  .  .  .
      John       .  .  .  .  .      .  .  .  .  .        .  .  .  .  .
      Harry      .  .  .  .  .      .  .  .  .  .        .  .  .  .  .
      Full-time  .  .  .  .  .      .  .  .  .  .
      Short-time .  .  .  .  .      .  .  .  .  .
      Quit work  .  .  .  .  .      .  .  .  .  .
      Retired    .  .  .  .  .      .  .  .  .  .
      Fired      .  .  .  .  .      .  .  .  .  .
      Porter     .  .  .  .  .
      Mechanic   .  .  .  .  .
      Salesman   .  .  .  .  .
      Painter    .  .  .  .  .
      Plumber    .  .  .  .  .
===========================================================================
SOLUTIONS
---------
    Happy Families: -Tom,soldier,Jane,four -Dick,airman,Joan,two
                    -Harry,sailor,Jean,three.
    Veterinary:     -Emily Bennet,parrot,fourth -Norah Wilson,cat,second
                    -Gregg Harding,cavey,third -Janice Jackson,rabbit,first
                    -Martin Merton,dog,last.
    Work Work Work: -Dave,60,porter,retired -Jack,56,plumber,fired
                    -Bill,50,painter,short-time -John,62,salesman,Full-time
                    -Harry,66,mechanic,quit work.
===========================================================================
    Not being an expert puzzle writer, I hope the above are error free.
    Finally,  why not try designing your own puzzles.  The Logic Buff will
be a great help checking if all your clues are essential.  A good puzzle
has just enough information to enable the chart to solve, with one or more
of the bits of information made indistinct.  If you include the solutions
and possibly your own set of Logic Buff rules for reference, you could then
upload the puzzles via the Internet for others to appreciate.
Enjoy and Happy Puzzling ..
-      The Logic Buff      -

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