* Mental Blocks *

* KMS Industries, Alexandria, VA, 1968. *

(plastic, 1.75 inches;

directions are in the bottom)

Each of the eight cubes has three colored rods going through it,
one in each of the x, y, and z directions
(four of the cubes have a
*red*, *blue*, and *white rod*,
two of the cubes have two reds and a white,
one has two reds and a blue,
and one has two whites and a blue).
Take the eight cubes out of the case and arrange them in a single 2x2x2 cube to make continuous rods of the same color passing through it: