yes, it does not matter if the y is at the beginning or at the end. However, most teachers usually prefer to have the y at the beginning as it is easier to read.
Answer = a
Explanation- A cube is a 3D figure and each face would be a square since it is a cube. Since each side is a square all the sides are the same Width, Length, and height. Therefor you would be multiplying whatever number your have by itself 3 times because the formula would be Length x Width x Height