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Help!!!! Is this rubix configuration solvable? These are the only two pieces in the wrong place.

If the answer is no, what pieces do I need to reconfig to make the cube solvable? Note that my kid may have accidentally flipped the corner piece or swapped a center while playing with the cubeenter image description here.

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  • $\begingroup$ Buy a new one will solve this :P $\endgroup$
    – Conifers
    Jul 31, 2019 at 5:25

1 Answer 1

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It is not possible to swap a single pair of edges by doing legal cube moves.

The simplest way to fix it is, well, to fix it: take it apart enough that you can bodily swap the two edge pieces back again.

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  • $\begingroup$ The best way to pop out an edge piece out is to rotate the top layer 45 degrees so that it is diagonal to the rest of the cube, and then slide the tip of a flat-head screwdriver (or a suitable fork handle, or what-have-you) under the edge piece. A gentle twist should pop the piece out without damaging the cube. $\endgroup$
    – Bass
    Jul 31, 2019 at 6:29
  • $\begingroup$ Thank you, Bass. Your tip on rotating it 45 degree on the top layer did the trick. $\endgroup$
    – Silverstar
    Jul 31, 2019 at 7:11
  • $\begingroup$ Just curious, is there a way to reverse engineer and figure out what corner or center pieces were moved? $\endgroup$
    – Silverstar
    Jul 31, 2019 at 7:12
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    $\begingroup$ No. All "swap a pair of sub-cubes" changes are equivalent in the sense that if you do one then there's a sequence of legal moves that makes it look like any other. There are also restrictions on edge-flipping and corner-twisting; they're a little more constraining but e.g. it's still true that flipping one edge by disassembly is "equivalent" to flipping any other. $\endgroup$
    – Gareth McCaughan
    Jul 31, 2019 at 11:04
  • $\begingroup$ If you swap one or three pairs of opposite centres, then I think you also end up looking as if one pair of edges or corners is swapped. I'm not sure I'd want to use the word "equivalent" there because of course the cube does then end up looking different in that you have a different arrangement of centres, and you can't ever change that by legal moves. $\endgroup$
    – Gareth McCaughan
    Jul 31, 2019 at 11:06

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