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

Redeem

NOT true for y?

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

NOT true for y?

by sanju09 » Wed Feb 24, 2010 2:39 am
If y^3 - x y^2 - 14 x^2 y + 24 x^3 = 0, then which of the following is NOT true for y?

I. y = 2 x
II. y = 3 x
III. y = 4 x

(A) III only
(B) II only
(C) I only
(D) III & II
(E) III & I
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: — Problem Solving |
User avatar
Legendary Member
Posts: 1275
Joined: Thu Sep 21, 2006 11:13 pm
Location: Arabian Sea
Thanked: 125 times
Followed by:2 members

by ajith » Wed Feb 24, 2010 3:01 am
sanju09 wrote:If y^3 - x y^2 - 14 x^2 y + 24 x^3 = 0, then which of the following is NOT true for y?

I. y = 2 x
II. y = 3 x
III. y = 4 x

(A) III only
(B) II only
(C) I only
(D) III & II
(E) III & I
Substituting

I. in the equation => 8x^3 - x*4x^2 - 28*x^3 +24x^3 = 0; I can be true
II. in the equation => 27x^3 - 9x^3 - 42 x^3 + 24 x^3 = 0; II can be true
III in the equation => 64x^3 - 16x^3 - 56x^3 +24x^3 = 16x^3 is zero only when x =0

And when x =0 and y =0 it is all true!

Given the choices I would choose III that is option A
Always borrow money from a pessimist, he doesn't expect to be paid back.
Top
Post new topic Post Reply
• Page 1 of 1