In 1998, a Hungarian professor, Dr. László Nagy, launched a fine website celebrating recreational mathematics:   Pentomino HungarIQa. (Love that IQ allusion in the name.) It introduced to Hungarian audiences the joys of pentominoes, tangrams, and a set of rhomboid pentominoes that László (Laci to his friends) had independently discovered a few years after Kate Jones first introduced Rhombiominoes^TM in 1990.

Laci (Luh-tsee) designed his pentarhombs different from Kate's in two important ways. Where Rhombiominoes are only the 20 distinct pentarhombs, the HungarIQa model is a full double set of left-slant and right-slant pentominoes, yielding 24 tiles in all (4 being their own duplicates). And where Rhombiominoes contains 3 colors so that a 10x10 grid can be filled with no two of the same color joined, Laci's set has just two colors, so the left slant and right slant subset each gets its own color.

The Pentomino HungarIQa website had an ongoing contest for the first solution to any of the listed figures, and a Hall of Fame of successful solvers' names. It is now closed, but you can still view the figures. So, what are the chances that the first two people to publish independently about turning pentominoes into rhombuses would both be Hungarian, half a globe apart?