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Re: exponents

by Stuart@KaplanGMAT » Sun Jun 08, 2008 6:22 pm
ssraf wrote:10^8-10^2/10^2-10^3 =

OA 10
I'm pretty sure you've misstated the denominator - it should be 10^7 - 10^3.

The key to answering this question is to recognize that 10^8 - 10^2 is really just 10^8 and that 10^7 - 10^3 is really just 10^7.

So, the question is really:

What's 10^8/10^7 = 10^1 = 10
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by VP_Jim » Sun Jun 08, 2008 6:24 pm
I don't think the answer to this one is 10 - did you have a typo?
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by ssraf » Sun Jun 08, 2008 6:57 pm
yes sorry Stuart is right, the denominator should have read 10^7-10^3.

Can you elaborate on your answer. Why is 10^8-10^2 simply 10^8?

Thanks!
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by VP_Jim » Sun Jun 08, 2008 7:23 pm
I think what Stuart means is that 10^8 (100,000,000) is such a huge number that subtracting 10^2 (100) from it is insignificant - it's still virtually 10^8.

Same for the denominator.

Incidentally, this one isn't too hard to work out since we're dealing with powers of 10.

We could just write out:

(100,000,000-100) / (10,000,000-1,000)

Which, as Stuart pointed out, is essentially the same thing as 100,000,000 / 10,000,000 = 10.
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Re: exponents

by VerbalAttack » Mon Jun 09, 2008 2:00 am
ssraf wrote:10^8-10^2/10^7-10^3 =

OA 10
Hi ssraf, if this is a Problem Solving question, could you provide with other answer choices as well please?

The answer is close to 10 but not exactly 10. Is it okay to compromise? GMAT being tricky its better to look at all the answer choices and the wordings.

Cheers
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