If the volumes of two cubes are in the ratio of 64 : 125, then what is the ratio of their total surface areas?

16 : 25

We know that,

Volume of cube = (side)³

Total surface area of a cube = 6(side)²

Let the edge of two cubes be a and b respectively

Now,

a³ : b³ = 64 : 125

a : b = 4 : 5

Ratio of total surface area = 6a² : 6b² = 4² : 5² = 16 : 25