yb wrote:

I think it is referring to the interior diagonal, since it says "diagonal of the cube", instead of "diagonal of a side of the cube".

1) and 2) both refer to cubes w/ a side of 10.

D stands.

Diagonal simply means the highest distance between 2 points in the cube. there can be only one highest distance between 2 points. for a cube digonal is simply sqrt(square of one side + square of one side's diagonal)

if x is the length side then diagonal = sqrt(x^2+2x^2)

= sqrt(3) * x

diagonal of one side = sqrt(x^2 + x^2)

= sqrt(2) * x

so if we know that the diagonal of a cube is 10*sqrt(3)

we know that x = 10

so voluve = 1000

so statement 2 is sufficient.

surface area = 6x^2 = 600

so, x^2 = 100

so volume = 1000

there fore D is the answer.

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hey ya......