2
$\begingroup$

There are 10 squares in the figure. Move 3 matchsticks to create 17 squares. Squares don't have to be equal in size?

enter image description here

$\endgroup$
5
  • $\begingroup$ $Move$ 3 matchsticks or $Remove$? $\endgroup$
    – Seyed
    Commented Dec 28, 2017 at 17:06
  • $\begingroup$ Mostly likely move... Remove would be impossible? @Seyed $\endgroup$
    – Quintec
    Commented Dec 28, 2017 at 17:07
  • 2
    $\begingroup$ The obvious solution has 17 squares and one extra match sticking out like a sore.. stick. This is, in general, an uncool thing: all the matches should be meaningful parts of the solution. I hope there is a less obvious solution that makes use of all the matches. $\endgroup$
    – Bass
    Commented Dec 28, 2017 at 17:12
  • $\begingroup$ It also means there is no unique solution. The sore-stick solution can be formed in 16 different ways. $\endgroup$
    – ekhumoro
    Commented Dec 28, 2017 at 22:02
  • 2
    $\begingroup$ Assuming there really is no clever "other solution", I'd like to suggest a slight modification: remove the middle stick in the vertical line of 5 sticks, and transform the problem into this famous one. Notice the lack of sore sticks, how the starting position is 4-way symmetric and the answer is not, and how all the squares in the starting position are non-adjacent, and the answer has squares crammed in as tight as possible. $\endgroup$
    – Bass
    Commented Dec 28, 2017 at 23:44

1 Answer 1

15
$\begingroup$

The answer is:

enter image description here

How:

Let's name the sticks.

enter image description here

Here 17 squares are- (1) ABCD, (2) GHIJ, (3) STUR, (4) CELM, (5) EFKL, (6) FKZJ, (7) KZWX, (8) LKXY, (9) MNYL, (10) NOPY, (11) PQXY, (12) QRWX, (13) CNXF, (14) MOQK, (15) EYWJ, (16) LPRZ, (17) CORJ

$\endgroup$
4
  • 11
    $\begingroup$ And it even has the antenna at O, with which it can communicate to the alternate universe where it’s ok for a matches puzzle to have matches left over after completing the objective. Not the answerer’s fault, of course, so here’s my upvote. $\endgroup$
    – Bass
    Commented Dec 28, 2017 at 19:13
  • $\begingroup$ @Bass I don’t know... maybe you’re from an alternate universe where all puzzles have to be perfect? (Not trying to be an ass... but you seem to be hating a lot over a small thing.) $\endgroup$
    – Quintec
    Commented Dec 28, 2017 at 21:49
  • 3
    $\begingroup$ @thecoder16, A good puzzle is always explicit about the desired objectives and the allowed means. Therefore, it’s very important to follow the generally accepted conventions, or at least add a note when deviating. In matchstick rearranging, some of the conventions are - no stacking - no breaking the matches - no overlapping - and, very importantly: no surplus. Otherwise the solution to this puzzle could be ”well, it clearly has two squares already. Just ignore the other squares.” $\endgroup$
    – Bass
    Commented Dec 28, 2017 at 22:52
  • 1
    $\begingroup$ @thecoder16 Also, please accept my apologies for using such unprofessional language in my criticism. I was a bit riled up since this wasn’t the first matches problem with the exact same issue on PSE today. I got a bit carried away. Sorry. $\endgroup$
    – Bass
    Commented Dec 28, 2017 at 22:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.