Mathematical and Physical Journal
for High Schools
Issued by the MATFUND Foundation
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Problem K. 222. (October 2009)

K. 222. The diagram below shows the nets of four cubes unfolded in a plane. There are line segments painted on the surface of each cube, and these are also shown in the diagram. (No line is drawn along the edges of the cubes.) For which cube will the lines form a closed loop?

(6 pont)

Deadline expired on November 10, 2009.

Sorry, the solution is available only in Hungarian. Google translation

Megoldás. Az \(\displaystyle 1\), \(\displaystyle 2\), \(\displaystyle 4\) számú kockák mindegyikén kapunk zárt töröttvonalat.


297 students sent a solution.
6 points:124 students.
5 points:36 students.
4 points:12 students.
3 points:16 students.
2 points:57 students.
1 point:17 students.
0 point:15 students.
Unfair, not evaluated:20 solutions.

Problems in Mathematics of KöMaL, October 2009