Question

The length, suface area of a cube is 256 sq- m , the volume of the cube is
A. `64 cm^3 `
B. `216 m^3 `
C. `256 m^3 `
D. `512 m^3`

Answer 1

Let the length of equal sides of the cube bea m .
`therefore ` the surface are of the cube `4a^2` sq-m . [ `because` the number of lateral surface is 4]
As per question `4a^2 = 256 or a^2 = (256)4 or , a^2 = 64 or, a = pm 8 `
but the value of a can never be nagative `therefore` a = 8
Hence the volume of the cube `=8^3` cubic-metre `=512 m^3`