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

Redeem

GMAT prep DS question

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Master | Next Rank: 500 Posts
Posts: 377
Joined: Wed Sep 03, 2008 9:30 am
Thanked: 15 times
Followed by:2 members

by schumi_gmat » Tue Apr 21, 2009 3:56 pm
IMO A

Slope of line l is 3/4 and find out if point (-2/3, 1/2) lies on line


Equation is y=3/4x + c
1. point (4, 4) lies on the line l

i.e 4 = 3/4 (4) + c
c = 1

therefore, y = 3/4 x + 1
when x = -2/3, y = 1/2. Hence (-2/3 and 1/2) lies on line l


2) similarly substitutinf (-4,-2), we get c = 1
and eqution becomes y = 3/4x +1

Same as Stmt 1

HEnce D .
Last edited by schumi_gmat on Wed Apr 22, 2009 9:15 am, edited 2 times in total.
Top
Legendary Member
Posts: 940
Joined: Tue Aug 26, 2008 3:22 am
Thanked: 55 times
Followed by:1 members

by iamcste » Tue Apr 21, 2009 6:34 pm
Take D from me


Using slope formula, -3x1+4y1=4

Stmt 1

Cordinates given suffice eqtn. so points are on line L sufficient

stmt 2

Cordinates given suffice eqtn. so points are on line L sufficient

@ Schumi- cordinates you used are incorrect for evaluating stmt 2.

even with incorrect values, you will atleast know that point doesnt like on line L

hence D
Top
Senior | Next Rank: 100 Posts
Posts: 47
Joined: Wed Oct 08, 2008 11:29 am
Location: Toronto, Ontario
Thanked: 5 times

by anayeri » Tue Apr 21, 2009 7:13 pm
Agree w/ D, I believe all you need here are other points on the line, to evaluate with (y2-y1)/(x2-x1) = slope.

what's OA?
Top
Master | Next Rank: 500 Posts
Posts: 377
Joined: Wed Sep 03, 2008 9:30 am
Thanked: 15 times
Followed by:2 members

by schumi_gmat » Tue Apr 21, 2009 10:37 pm
Thanks Iamcste.

I have edited my post.

One question:

How do you know that y-intercept =4
in equation is -3x+4y=4

I thought we have to calculate the y-intercept in bith the conditions.

Stmt 2 satisfies the equation the equation -3x+4y=4

How did you get the same equation for both statements
Top
Legendary Member
Posts: 876
Joined: Thu Apr 10, 2008 8:14 am
Thanked: 13 times

by ketkoag » Tue Apr 21, 2009 11:48 pm
D for me as well coz in the line intercept form by statement 1 and 2 individually, put the coordinates and u'll get that the coordinate is satisfying both the equations.
hence D.
Top
Master | Next Rank: 500 Posts
Posts: 377
Joined: Wed Sep 03, 2008 9:30 am
Thanked: 15 times
Followed by:2 members

by schumi_gmat » Wed Apr 22, 2009 9:16 am
Thanks everybody.

I have editted my post for the mistake I did.
Top
Post new topic Post Reply
• Page 1 of 1