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surface area & cubes

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guest612
 Post subject: surface area & cubes
 Post Posted: Mon Mar 10, 2008 8:14 pm 
Question: Each edge of a cubical block of wood measures 2 inches. What is the surface area of the block in square inches?

Answer: 4.
I thought answer was 8. Why is it 4 and not 8? I thought it was 2x2x2. If that gives volume and not surface area, then wouldn't surface area be the sum of all six sides therefore 2x6=12? How do you arrive at 4? Do they mean what is the surface area of one side of the block? But that would be 2x2. Ugh. I'm so confused. And I don't see how it can be 1+1+1+1 if each edge is 2. Please help!

Thank you.
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Guest
 Post subject:
 Post Posted: Tue Mar 11, 2008 12:36 pm 
Surface area of a cube = 6 * (a^2)
where a^2 is area of a side, and 6 because cube has 6 sides. The answer would be 24.
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guest612
 Post subject:
 Post Posted: Tue Mar 11, 2008 6:51 pm 
thanks. the answer was 4. do you know how that could be?
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RonPurewal
 Post subject:
 Post Posted: Wed Mar 12, 2008 4:19 am 
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ManhattanGMAT Staff


Posts: 7146
please post a source for this question, or we'll have to kill the thread. (even if you just made the problem up yourself, you still have to cite the 'source' of the problem, just to ensure that we aren't posting banned material.)

thank you.
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guest612
 Post subject:
 Post Posted: Thu Mar 13, 2008 1:15 pm 
Sorry! Answer is E. 24. I understand it now. It's 2 inches making the area of one side 4. Multipy4 by the 6 faces to result in 24.

the source was test code #37 section 1, #7.

Thank you.
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RonPurewal
 Post subject:
 Post Posted: Fri Mar 14, 2008 4:40 am 
Offline
ManhattanGMAT Staff


Posts: 7146
no problem.
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