Place 18 1x1x5 sticks in a 5x5x5 cube so that it is not possible to place a 19th stick in the cube.
The minimum required to block any more is 12: Three sets of 4 laying against mutually perpendicular sides.
This is easily extended to 18
Bottom layer has 4 flat and two standing upright:
AAAAA
BBBBB
CCCCC
DDDDD
-E-F-
Each additional layer has three flat perpendicular to the bottom (GHI becomes JKL etc):
G-H-I
G-H-I
G-H-I
G-H-I
GEHFI
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Posted by Jer
on 2017-04-12 14:55:44 |
Solution
