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Kaplan practice test question

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Junior | Next Rank: 30 Posts
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Kaplan practice test question

by cooperbaker » Sat Dec 20, 2008 7:14 pm
What is the value of 7q-p

(1) p+3q = 3
(2) 2p-4q = -5

I got this wrong on my practice test, however Kaplan's explanation of why the answer is C is not very explanatory. I chose E, seeing as how everything is a linear equation with TWO unknowns.

HELP!!
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Source: — Data Sufficiency |
Junior | Next Rank: 30 Posts
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wow...

by cooperbaker » Sat Dec 20, 2008 7:20 pm
I feel stupid... you don't even really have to work the math, variable isolation. :roll:
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by cramya » Sat Dec 20, 2008 7:21 pm
It is possible to solve for p and q with 2 equations (2 unknowns 2 equations).

Or u can subtract 2 from 1 and it gives u 7q-p value directly.

p+3q - ( 2p-4q ) = 3 - (-5)

p+3q-2p+4q = 8

7q-p = 8

C)
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by vishubn » Sat Dec 20, 2008 7:36 pm
(2)-(1)--- thats it

OA C

vishu
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by vittalgmat » Mon Dec 22, 2008 3:00 am
This is fairly easy..
Each stmt by itself is insufficient

While combining, one needs to verify whether the eqns are UNIQUE (ie. one eqn cannot be derived from the other). Once this is verified, we dont have to solve: 2 unique eqns, 2 variables.. Done.
Ans C
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