Soma cube cube problem. There are 240 distinct solutions of the Soma cube puzzle, excluding rotations and reflections: these are easily generated by a simple recursive backtracking search computer program similar to that used for the eight queens puzzle. Current world record for the fastest time to solve a soma cube is 2.93 seconds and was set by Krishnam Raju Gadiraju, India. The seven Soma pieces are six polycubes of order four, and one of order three: Piet Hein authorized a finely crafted rosewood version of the Soma cube manufactured by Theodor Skjøde Knudsen's company Skjøde Skjern (of Denmark). Beginning in about
Rubik's Cube minus the number of unsolved cubes after one hour has elapsed. In fewest moves solving, the contestant is given one hour to find his or her solution and must write it down. There are different variations of Rubik's Cubes with up to thirty-three layers: the 2×2×2 (Pocket/Mini Cube), the standard 3×3×3 cube, the 4×4×4 (Rubik's Revenge/Master Cube), and the 5×5×5 (Professor's Cube) being the most well known. The 17×17×17 "Over The Top" cube (available late 2011) was until December 2017 the largest (and most expensive, costing more than two thousand dollars) commercially sold cube. A working design for a 22×22×22