ratio?

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by GMATGuruNY » Sat May 07, 2011 4:13 pm
katknms9 wrote:Hopefully not beating a dead horse with this clarification, but if after simplifying the initial equation to get:

-1/10 < n

How is taking the reciprocal of n (1/n) not equal to -10 < n?

My logic is:
-1/10 < n so...
1/(-1/10) < 1/n
-10 < 1/n

I'm obviously missing something, so if someone could help me out that would be great. I understand the logic of plugging values to see why "A" makes sense, just wanted to try and see why the above rationale doesn't make sense.
When you take the reciprocal of each side of an inequality, the direction of the inequality must change:

3 > 2, but 1/3 < 1/2.
-2 > -3, but -1/2 < -1/3.

Thus, if -1/10 < n, then -10 > 1/n.
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by katknms9 » Sun May 08, 2011 7:13 am
Got it. I knew there had to be a rule I was missing.

Thank you GMATGuru.