BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

x2 + y2 vs (x +y)2

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Master | Next Rank: 500 Posts
Posts: 158
Joined: Wed Jun 16, 2010 8:21 am
Thanked: 13 times
Followed by:1 members

x2 + y2 vs (x +y)2

by rohit_gmat » Mon Oct 17, 2011 4:51 am
Is x^2 + y^2 > 100 ?

1) 2xy < 100

2) (x + y)^2 > 200

OAC

I plugged in numbers. Anyone can explain why B is wrong? I tried plugging in.. is it the best method here? Any set of numbers that will prove it insufficient?

Thanks
Top
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Mon Oct 17, 2011 5:55 am
rohit_gmat wrote:Is x^2 + y^2 > 100 ?

1) 2xy < 100

2) (x + y)^2 > 200

OAC

I plugged in numbers. Anyone can explain why B is wrong? I tried plugging in.. is it the best method here? Any set of numbers that will prove it insufficient?

Thanks
You are correct, the OA for that question is actually B.

Please see: https://www.beatthegmat.com/x2-y2-t92678.html

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Post new topic Post Reply
• Page 1 of 1