32.80%
37.50%
72.80%
None of the above
Answer is Wrong!
Answer is Right!
The correct answer is (c).
The volume of a cube is given by the formula $V = s^3$, where $s$ is the side length of the cube. If the side length is increased by 20%, then the new side length is $1.2s$. The new volume is then $V = (1.2s)^3 = 1.728s^3$, which is an increase of 72.8%.
Option (a) is incorrect because it is the percentage increase in the side length, not the volume. Option (b) is incorrect because it is the percentage increase in the area of a face of the cube, not the volume. Option (d) is incorrect because it is not one of the possible answers.