Question

3 cubes of 3:4:5 are melted to for a cube of 12 cm find the edges

Answer 1

Let each side of cube be 3x ,4x, 5x
Then sum volume of each cube is =27x^3+64x^3+125x^3
=216x^3
Volume of new cube formed=12×12×12=1728.
Therefore 216^3=1728
=》x^3=1728÷216
=》x^3=8
=》x=2
Therefore, edges are 6, 8 and 10

Answer 2

let edges of cubes be 3x, 4x, &5x
then,
Sum of the volumes of the cubes = volume of cube of edge 12 cm
27x³ + 64x³ + 125x³ = 1728cm³
216x³ = 1728cm³
x³= 1728cm³/216
x³= 8
x=2
edges of cubes are 6cm,8cm& 10cm