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

Redeem

(x + y) (1/x + 1/y) = 4

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

(x + y) (1/x + 1/y) = 4

by sanju09 » Thu Aug 12, 2010 3:31 am
Is x = y?

(1) (x + y) (1/x + 1/y) = 4.
(2) (x - 50) ^2 = (y - 50).


[spoiler]Source: freegmattest.net[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Data Sufficiency |
User avatar
Legendary Member
Posts: 1893
Joined: Sun May 30, 2010 11:48 pm
Thanked: 215 times
Followed by:7 members

by kvcpk » Thu Aug 12, 2010 3:47 am
sanju09 wrote:Is x = y?

(1) (x + y) (1/x + 1/y) = 4.
(2) (x - 50) ^2 = (y - 50).


[spoiler]Source: freegmattest.net[/spoiler]
(1) (x + y) (1/x + 1/y) = 4.
(x+y)^2 -4xy=0
(x-y)^2 = 0
Hence x-y = 0 -> x=y
SUFF

(2) (x - 50) ^2 = (y - 50).
take x = y = 50.. YES
0=0
take x=53, y=59.. NO
3^2 =9
INSUFF

pick A
"Once you start working on something,
don't be afraid of failure and don't abandon it.
People who work sincerely are the happiest."
Chanakya quotes (Indian politician, strategist and writer, 350 BC-275BC)
Top
User avatar
Legendary Member
Posts: 1460
Joined: Tue Dec 29, 2009 1:28 am
Thanked: 135 times
Followed by:7 members

by selango » Thu Aug 12, 2010 3:49 am
x=y?

stmt1,

(x+y)(x+y)/xy=4

(x+y)^2/xy=4

Sub x=y

(2y)^2/y^2

4y^2/y^2=4

suff

stmt2,

(x - 50) ^2 = (y - 50).

sub values x=60,y=150;x!=y

sub values x=50,y=50,x=y

Insuff

Pick A
--Anand--
Top
Post new topic Post Reply
• Page 1 of 1