Question

The lengths of the sides of three cubes are in the ratio 3:2:1.

(a) If the total surface area of the smallest cube is 22 cm2, find the total surface area of the largest cube.                                        
(b) If the volume of the largest cube is 81 cm3, find the volume of the second largest cube.​

Answer 1

Let the side of three cube be 3x, 2x and x

so,

area of the smallest cube =6a²

22cm² =6x²

22cm²/6. =x²

11/3 =x²

x. =√11/3

so, side of largest cube =3x=3√11/3c

so, t. s. area of largest cube =6a²

=6(3√11/3)²

=6×33= 198cm²

Answer 2

(a) total surfac3 area = 198cm²