Kaplan DS - Cube

[swadeep]

The base of a rectangular block has an area of 60 square centimeters. Is the block a cube?

(1) The area of the front face of the block is 60 square centimeters.
(2) The area of a side of the block is 60 square centimeters.

My answer is that we cannot solve this question even if we use both the statements. But the Official Answer in Kaplan is something else. Am I right or someone feels that what Kaplan says is right. I will post the Official Answer later.

[pach2212]

I guess C is the answer.

Assume the three sides to be a,b,c

In the question, given a*b = 60

Statement 1 says:
b*c = 60. Hence we have a=c.
But do not know whether a = b??? So insufficient

Statement 2 says:
a*c=60. Hence we have b=c.
Again it is insufficient since, we do not know whether a=b?

Combining the 2 statments we get a=b=c.
So we can confirm that the block is a cube.

Hence C

[swadeep]

agreed that from the two statements we know that the L=B=H and all the 6 faces have the same area. But the statements do not tell whether the angle subtended by these faces is 90. In such a case the solid need not be a cube, it can be a parallelopiped. And for this reason I chose (D) as the answer. But the Official Answer is (C) for the same reasons that you have stated. Can someone please clarify this for me.

[gmat_for_arun]

My answer is also C. I assume that when they say 'rectangular block', it means that all sides are perpendicular. Do you think that this assumption is right?

[swadeep]

"I assume that when they say 'rectangular block', it means that all sides are perpendicular"Perfect ! How dumb of me to miss that. I guess I thought a bit too much for this question !

Thanks Guys.

[rd_eastbay]

Agreed with Official Answer.