Esurance Interview Question: you have a 9x9x9 sided cube m... | Glassdoor

## Interview Question

Actuarial Analyst Interview San Francisco, CA

# you have a 9x9x9 sided cube made up of 1 squaree inch

squares. If all sides are painted how many cubes have no paint on any side?
Answer

## Interview Answer

6 Answers

1

Zero... because all sides are painted; either you re-wrote this wrong or you trying to walk her through mathematical equations to answer this obviously simple question is the reason you didn't get an offer.

Eric on Feb 12, 2013
3

Eric, calm yourself. Im guessing he means that all sides (like he said) are painted. i.e. only the cubes on the outside of the cube. So the way to solve would be think of an 8x8x8 cube inside of a 9x9x9 cube, where are all of the 8x8x8 cube pieces have no paint on them. I think the answer is 8 cubed or 512 then, but dont quote me on that.

Andrew on Feb 27, 2013
15

Since cubes on all sides are painted, I believe that you would need to eliminate a cube from each side, so I think that the answer is 7x7x7 = 343

John on Mar 12, 2013
2

I agree with John's answer, but the wording is terrible. You have to assume that the cube is built from 9^3 one inch cubes. Then the problem becomes simple to visualize and solve. I hope the interview explained the problem clearer than this poster.

Patrick on Feb 4, 2014
1

shuld be one ?, 3 cubes on on x axis, 2 on y side , 2 on z side , if all sides are painted..we will only be left with middle cube which is common cube and cannor be painted,,

james on Apr 10, 2014
3

To add in general for nXnXn cube the answer is (n-2)X(n-2)X(n-2)

Anonymous on Jul 23, 2015

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