Tricky question

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 133
Joined: Sat Dec 29, 2007 2:43 am
Thanked: 12 times

Tricky question

by raju232007 » Mon May 03, 2010 9:06 am
Is x>3?

1. x^2>9
2. sqrt(x)>1.5

1. From statement 1 we have x<-3 and x>3
Insufficient
2. From the second statement we get x>2.25 ( By squaring on both sides)
Insufficient

By combining two statements
we can conclude that x is positive and x>2.25 and x>3
But still we can't say whether x>3 or not.... So E should be the answer..But the ans is C...

Can someone give a brief explanation on this one..

Junior | Next Rank: 30 Posts
Posts: 17
Joined: Sat Apr 25, 2009 11:40 am
Thanked: 2 times

by sandy_online » Mon May 03, 2010 9:12 am
x>3 and x>2.5 => x>3 so it's C.

we can see other way:
since either x<-3 or x>3 from statement 1.
but from statement 2, since x !<-3 hence => x>3

Legendary Member
Posts: 2326
Joined: Mon Jul 28, 2008 3:54 am
Thanked: 173 times
Followed by:2 members
GMAT Score:710

by gmatmachoman » Mon May 03, 2010 10:34 am
raju232007 wrote:Is x>3?

1. x^2>9
2. sqrt(x)>1.5

1. From statement 1 we have x<-3 and x>3
Insufficient
2. From the second statement we get x>2.25 ( By squaring on both sides)
Insufficient

By combining two statements
we can conclude that x is positive and x>2.25 and x>3
But still we can't say whether x>3 or not.... So E should be the answer..But the ans is C...

Can someone give a brief explanation on this one..
Ok try few numbers between 3 & 2.25

Say X= 2.7
as per st 1 X^2 > 9
IS 2.7^2 >9??? No....So we can't have X <3...That means X >3.

Pick C