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)

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.

cube brain teaser

Click to read Hint #1.

Click to read Hint #2.

Click to read Hint #3.

Click to read Hint #4.

Click to read the Solu­tion and Expla­na­tion.

Posted in


  1. Masa on April 26, 2007 at 10:22

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

  2. Caroline on April 26, 2007 at 11:33

    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 on May 2, 2007 at 12:21

    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 √2. V = side length cubed. 2*√2.

  4. Caroline on May 7, 2007 at 9:20


    Thanks for anoth­er, very valid explanation!

  5. r on September 6, 2007 at 6:54


  6. Alana on October 16, 2007 at 9:55

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

  7. Alvaro on October 16, 2007 at 10:20

    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 on November 7, 2007 at 11:15

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

    V = √2 x √2 x √2

  9. Sheri on December 6, 2007 at 6:38

    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 on December 6, 2007 at 9:17

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

  11. Mitch on January 6, 2008 at 2:43

    Yea i found this one very easy.

  12. fluffychenille on January 27, 2008 at 1:02

    Just cre­ate anoth­er linked “web­page” for the answer.…the down­load is annoying.

  13. tayler on February 6, 2008 at 12:34

    i love dr. nasty =)

  14. mathlete on April 15, 2008 at 8:06

    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 on October 15, 2009 at 7:16

    The old­er side is 1 Foot.

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

    √2 x √2 x √2 = 2√2 = 2.828 cubic feet.

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SHARPBRAINS is an independent think-tank and consulting firm providing services at the frontier of applied neuroscience, health, leadership and innovation.
SHARPBRAINS es un think-tank y consultoría independiente proporcionando servicios para la neurociencia aplicada, salud, liderazgo e innovación.

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