Question -
Answer -
Let the edges of threecubes (in cm) be 3x, 4x and 5x respectively.
So, the volume of thecube after melting will be = (3x)3 + (4x)3 +(5x)3
= 9x3 +64x3 + 125x3 = 216x3
Now, let a be the edgeof the new cube so formed after melting
Then we have,
a3 =216x3
a = 6x
We know that,
Diagonal of the cube= √(a2 + a2 +a2) = a√3
So, 12√3 = a√3
a = 12 cm
x = 12/6 = 2
Thus, the edges of thethree cubes are 6 cm, 8 cm and 10 cm respectively.