How do you change the edge of a cube so that its volume decreases 27 times?

Initially, we have a cube with side x, since it is known that the volume of the cube is a ^ 3, then the volume is:
V1 = a ^ 3 = x ^ 3.
We have a second volume, which is 27 times less, it is easy to find the number that gives (1/27) in the cube, this is the number (1/3), check:
V2 = b ^ 3 = (1 / 3x) ^ 3 = (1/27) * x ^ 3, then the ratio of V2 to V1:
V2 / V1 = ((1/27) * x ^ 3) / x ^ 3 = 1/27.
Answer: the side needs to be reduced by 3 times.