A cube of side 9 cm made of iron is melted and recast into 8 small cubes. Find the side (in cm) of each small cube.

Correct option is B

Given:
Side of the original cube = 9 cm
Number of small cubes = 8
Formula Used:
Volume of a cube = side³
Total volume remains same after melting and recasting
Solution:
Volume of original cube = 9³ = 729 cm³
Let the side of each small cube be x cm.
Volume of one small cube = x³
Total volume of 8 small cubes = 8x³
According to the question:
8x³ = 729
​$$x^3 = \frac{729}{8} \\\ \\x = \sqrt[3]{\frac{729}{8}} \\\ \\x = \frac{9}{2}$$​​
x = 4.5 cm