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Extreme Values Question

Expert replies
by missrochelle » Wed Aug 04, 2010 6:39 am
If c < 4, what is the range of possible values for d if 3c = -6d.

I tried to solve by isolating d: d = - 1/2 C

Then plugging in numbers for c:
C = then D =
3 -3/2
2 -1
1 -1/2.

Clearly this was wrong because it was an extreme value question where I was supposed to plug in "LT4) in the equation.

My question is how does one easily identify Extreme value questions? What wording should you look for and what flags might there be to tell you you're doing it wrong and SHOULD be using extreme value strategy?

*source: ManhattanGMAT Flashcards*
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Source: — Problem Solving |

by missrochelle » Wed Aug 04, 2010 6:41 am
Also the answer is d > -2.
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by selango » Wed Aug 04, 2010 6:44 am
No need to plug values

c<4

3c<12

3c=-6d

-->-6d<12

d>-2

Hope this clarify
--Anand--
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by missrochelle » Wed Aug 04, 2010 6:51 am
thanks a lot.... definitely much easier to manipulate the inequality than to try to use Extreme Values.
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by selango » Wed Aug 04, 2010 7:27 am
missrochelle,

This is Inequality problem.To get the solution just solve the given equation.
--Anand--
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by missrochelle » Wed Aug 04, 2010 7:29 am
Thanks. The MGMAT explanation solved with with Extreme value (C = LT4, etc) which is where I got that notion. I prefer your way! Simple.
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