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'Coordinate Challenge' printed from http://nrich.maths.org/
We had lots of solutions to this problem but
not many of you told us how you got your solutions. Luis and
Freddie, who go to Newton Prep, sent in well-explained solutions.
Here is what Luis wrote:
The first thing I worked out is that the letter at (4,2) is not
symmetrical in any way, the only letter that isn't symmetrical in
any way is the letter P.
Then I worked out that at (0,2) and (1,2)
are the ends of the alphabet and had to be A and Z but I needed to
know which one went where so I looked at the clues. One said that
(0,2) and (2,0) have rotational symmetry which means that A is on
(1,2) and Z is on (0,2).
Then I saw the clue that said that (3,3),
(3,2) and (3,1) are all consecutive in the alphabet, because the A
and the Z are already used, it has to be C, D and E because it says
that (3,3) is made of only curved lines.
Then I saw that one of the clues said
that (2,0) is only made of curved lines, so (2,0) is the S.
(4,2) is not symmetrical in any way so (4,2) is a P.
The first clue says that (1,1) and (1,3)
have a vertical line of symmetry, another clue says that (1,1) also
has a vertical line of symmetry, which means that (1,1) is a X and
(1,3) is a Y, which leaves the B which is at (2,1) because a clue
says that at (2,1) there is a letter with a horizontal line of
Many children from
Stradbroke Primary School sent an image of their solution. Here is