If n 0 , which of the following must be true?

Question

If n > 0 , which of the following must be true?

I n^2 > 1
II n - n^2 < 0
III 2n - 1 > 0

A. I only 
B. II only 
C. III only 
D. I and II only 
E. none

varundixitmro2512 · Answer

IMO E

take n as 0.1 or 0.001, all the statements wont be true

Abhishek009 · Answer

I. True for all values of n except 1
 
When n = 1 ; n^2 = 1

II. True for all values of n except 1
 
When n = 1 ; n - n^2 = 1 - 1 =>0

III True for all values of n

Hence the correct answer will be (E)

prabhakar09 · Answer

I not true for anything <1. ~0.5
II not true for anything <1 
III not true for anything <0.5

KSBGC · Answer

Note: n is positive but we don't know whether it is an integer or fraction.

I. n^2>1. NOT necessarily . let x be 1/2.

II. n - n^2 <0. Let x be 1/2. False.

III. 2n - 1 > 0. let x be 1/2. 2*1/2 - 1 =0. False.

Thus , none of these options are correct. This question is designed to test fractional case.

The best answer is E.

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

If n > 0 , which of the following must be true?

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Problem Solving (PS) Questions

If n > 0 , which of the following must be true?

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards