Question

If three metallic solid cubes whose edges are $3cm,4cm$ and $5cm$ are melted and formed into a single cube, then the edge of the cube so formed is

• A. $5cm$
• B. $9cm$
• C. $7cm$
• D. $6cm$

Answer 1

The correct option is D $6cm$

Given, Edges of the $3$ metallic cubes are $3$cm,$4$cm,$5$cm

Their total volume

$={\left(3\right)}^3+{\left(4\right)}^3+{\left(5\right)}^3=24+64+125=216{cm}^3$

Volume of the new cube so formed$=216{cm}^3$

$\therefore$ each side of the cube formed $=\sqrt[3]{3216}=6cm$