inequalities

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 301
Joined: Tue Apr 22, 2008 6:07 am
Thanked: 2 times

inequalities

by beater » Thu Oct 02, 2008 3:23 pm
If x > 0, is x^2 < x ?
(1) 0.1 < x < 0.4
(2) x^3 < x^2

User avatar
Master | Next Rank: 500 Posts
Posts: 316
Joined: Mon Sep 22, 2008 12:04 am
Thanked: 36 times
Followed by:1 members

Re: inequalities

by Morgoth » Thu Oct 02, 2008 3:45 pm
beater wrote:If x > 0, is x^2 < x ?
(1) 0.1 < x < 0.4
(2) x^3 < x^2
Statement (1)
0.1 < x < 0.4
If fractions are taken
x^2 will always be less than x. Sufficient.

Statement (2)
if x>0
only way x^3 < x^2 is when 0<x<1
therefore, x^2<x. Sufficient.

Thus, D.

OA?

Master | Next Rank: 500 Posts
Posts: 301
Joined: Tue Apr 22, 2008 6:07 am
Thanked: 2 times

by beater » Thu Oct 02, 2008 8:51 pm
OA - D. Thanks!