## Brain Teaser: Dr. Nasty’s Giant Cube

Here is another mind-bender created by Wes Carroll for the SharpBrains readers.

Presenting …
Dr. Nasty’s Giant Cube

Difficulty: HARDER
Type: HYBRID (Logic/Spatial)

Question:
The diabolical Dr. Nasty has turned his Growth Ray on a perfect cube that used to measure one foot on a side. The new larger cube has twice the surface area of the original. Find the volume of the larger cube.

Click to read the Solution and Explanation.

### 16 Responses

1. Masa says:

Damn, this is propably the easiest puzzle you have ever posted here.

2. Caroline says:

Masa, I’m glad to hear you’re sharp enough to get this one so quickly! Not everyone else has. We’ll post another one tomorrow – come back and see how you do!

3. Sandman says:

I don’t like the explanation becasue it relies on rules of thumb. It’s simlple to go to the fundamental equations for SA and V. Each side is 1 X 1. Times 6 sides = 6. Double that is 12. Solve for side length gives Ã¢Ë†Å¡2. V = side length cubed. 2*Ã¢Ë†Å¡2.

4. Caroline says:

Sandman,

Thanks for another, very valid explanation!

5. r says:

giggity.

6. Alana says:

It is annoying to have to download the answers and hints to Word. Can’t you make it part of the website?

7. Alvaro says:

Hello Alana, we stopped using this Word system to display answers, given feedback like yours. The answers to most teasers are now easier to find. Thanks.

8. Beck says:

To use the basic volume equation V = H x L x W,

V = Ã¢Ë†Å¡2 x Ã¢Ë†Å¡2 x Ã¢Ë†Å¡2

9. Sheri says:

I agree with Alana, it is very annoying to download the hints and answers and usually I don’t. It would be much better if you could just click and read!!

10. Alvaro says:

Hello Sheri, OK, let us think how to make it easier to check the answer. Thanks for the feedback.

11. Mitch says:

Yea i found this one very easy.

12. fluffychenille says:

13. tayler says:

i love dr. nasty =)

14. mathlete says:

technically you cant double a ‘perfect’ cube…the answer is irrational…triple a cube yes , never double…well i think so anyway

15. R V says:

The older side is 1 Foot.

As the new area of one side is now 2 square feet, then one side becomes âˆš2 feet (or 1.414 feet). Now the Volume is:

âˆš2 x âˆš2 x âˆš2 = 2âˆš2 = 2.828 cubic feet.

Categories: Brain Teasers