Question

if the length of each edge of a cube is doubled, how many times does its volume and surface area become

Answer 1

the volume will become 8times of its previous value
the surface area will become 4times of its previous value

Answer 2

Let the length of the edge be x units
Now,
Volume = a³
Total Surface area =6a²
Double the side, that means
a*2= 2a
Volume= (2a)³=8a³
Total Surface Area= 6(2a)²=6*4a²=24a²

Therefore, volume increases 8 times whereas Surface area increases 4 times. Hope it helps!