What is f2l Rubiks?
First Two Layers, or F2L refers to the first two bottom layers of the 3x3x3 cube, or essentially all layers up until the last layer on larger cubes.
What is the hardest 3×3 Rubik’s cube?
Pentamix
1. The Pentamix may be the hardest take on Ernő Rubik’s Cube. This Pentamix is certainly a sight to behold. It is considered to be one of the hardest Rubik’s cubes to solve.