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

Redeem

what is the answer?

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 512
Joined: Mon Jun 18, 2012 11:31 pm
Thanked: 42 times
Followed by:20 members

what is the answer?

by sana.noor » Wed Jul 17, 2013 1:30 am
In the xy plane, if line k has negative slope and passes through the point (-5, r), is the x intercept of line k positive?

1) The slope of line k is -5
2) r>0
Work hard in Silence, Let Success make the noise.

If you found my Post really helpful, then don't forget to click the Thank/follow me button. :)
Top
Source: — Data Sufficiency |
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Wed Jul 17, 2013 3:24 am
In the xy-plane, if line k has negative slope and passes through the point (-5, r), is the x-intercept of line k positive?

1) slope of line k is -5
2) r > 0


oa-E
Many slope problems are best solved by DRAWING.

Statement 1: Slope = -5
Statement 2: When x = -5, r > 0

Both statements are satisfied by the following cases:

Case 1:
Image

Here, the x-intercept is negative.

Case 2:
Image

Here, the x-intercept is positive.

Thus, the two statements combined are INSUFFICIENT.

The correct answer is E.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
Junior | Next Rank: 30 Posts
Posts: 18
Joined: Tue Nov 29, 2011 1:17 am
Thanked: 1 times

by swathi8388 » Wed Jul 17, 2013 3:34 am
My guess is that the answer is E.

We know that slope is negetive and passes through (-5,r) the question is to find the x intercept.

let k's equation be y=mx+c , x intercept is the value when y=0 , so plugging in y=0 in the equation we get 0=mx+c or x=-c/m , and the quesiton is wheter -c/m is positive or not.

1. says that m is -5 so we kno that x= -c/-5 = c/5 , but since we do not know whether c is -ve or +ve this option doesnt help us.

2. r>0 which means the line passes throuh (-5,r) where r is a positive number

hence plugging in the values in k's equation x=-5 and y=r we get r = -5m+c

since we dont know the numerical value of r we dont know whether the value of c is +ve or -ve which means we cant predict the value of -c/m
Top
Post new topic Post Reply
• Page 1 of 1