Data sufficiency (2)

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Lookingfor700GMAT
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Topic: Data sufficiency (2)

Thu Mar 11, 2010 7:24 am

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Is 1/p > r/r^2 + 2?

p=r
r>0

I chose A by itself but the answer is C. Is this because the inequality would not hold if both p and r =0?

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kstv
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Thu Mar 11, 2010 11:24 am

the eq is 1/p> r/(r²+2) if p=r then 1/r > r/(r²+2) if r = 2 1/2>2/6 1/2>1/3 0.5> .333 but if r = -2 -1/2 < - 1/3 - 0.5 < - .3 on the number line we need the info that r > 0

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Thu Mar 11, 2010 11:58 am

Moved to the appropriate forum. The GMAT Math is strictly for general questions. Use the PS and DS forums for questions! _________________ Beat The GMAT Practice Questions - yay! Amsterdam

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Wed May 12, 2010 12:56 pm

Lookingfor700GMAT wrote: Is 1/p > r/r^2 + 2? p=r r>0 I chose A by itself but the answer is C. Is this because the inequality would not hold if both p and r =0? hi, i will solve this problem by different way... i choose C for the answer and here is my solution. 1/p>r/(r^2+2)? 1. p=r >>>> 1/r>r/(r^2+2) <=> 1/r-1/r^2+2 >0 <=> 2/r^3+2r>0 if r>0 ok, yes, 2/r^3+2r >0 if r<0 so no, >>>>> 1 is insuff 1. R>0 but what abot p? (N) 2 is insuff 1+2 is the answer C