The volumes of 3 solid cubes made of metal are 125 cm3, 64 cm3 and 27 cm3 respectively. After melting all the three cubes, a solid cube is made. Find the edge of the new cube.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 6 cm
Melting and recasting changes the shape but not the volume of the metal, so the new cube holds the three volumes together, and its edge is the cube root of that total.
Volume of the new cube \(=125+64+27=216\,\mathrm{cm^3}\)
Edge \(=\sqrt[3]{216}=6\) cm, since \(6\times6\times6=216\)