The answer is 5.5 m.
Cube
Volume = length x width x height
Since the length, width and the height are the same in cube, the formula can be:
Volume = length^3
Let x metres be the side length of the cube.
166 = x^3
x = ∛166
x = 5.495864.....
x = 5.5 (nearest tenth)
3.20 ÷ 2 = 1.6
3.20 + 1.6 = 4.8 (2 for $4.8)
4.8 x 8 = $19.20
The answer should be 8
5*4*6=120
4+(6+9)=19
675+9=75