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

Redeem

Distinct Line K and L intersect at (3, -2)

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Mon Apr 06, 2015 7:43 am

Distinct Line K and L intersect at (3, -2)

by muhammedz786 » Wed Jan 06, 2016 5:26 am
Distinct Line K and L intersect at (3, -2) (in coordinate plane). Is the larger angle formed at the intersection between these two lines are greater than 90 deg?

1) Lines k and l have positive y - axis intercepts

2) The distance between the y-axis intercepts of lines k and l is 5.


I saw this problem in MGMAT advanced quant book chap 7 problem set #4. I understand the first half of the answer explanation. However, I cannot understand the second part.

Can someone please help. I added the answer choices below.
Attachments
IMG_4753.jpg
IMG_3854.jpg
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 Jan 06, 2016 8:52 am
Lines k and l intersect in the coordinate plane at point (3, -2 ). Is the largest angle formed at the intersection between these two lines greater than 90°?

(1) Lines k and l have positive y-axis intercepts.
(2) The distance between the y-axis intercepts of lines k and l is 5.
If lines k and l are perpendicular, they will form four 90 degree angles.
If lines k and l are not perpendicular, they will form two angles less than 90 degrees and two angles greater than 90 degrees.

Question rephrased: Are lines k and l perpendicular?

Many slope questions are best solved by DRAWING.

Statement 1:
Since each line has a positive y-intercept and passes through (3,-2), the two lines cannot be perpendicular:
Image
SUFFICIENT.

Statement 2:
Case 1: Lines k and l are perpendicular, and the two y-intercepts are EQUIDISTANT from (3,-2).
Image
Here, the distance between the y-intercepts = 6.

Case 2: Lines k and l are perpendicular, and the two y-intercepts are NOT EQUIDISTANT from (3,-2).
Image
Here, the distance between the y-intercepts > 6.

Thus, if lines k and l are perpendicular, the MINIMUM distance between the y-intercepts is 6.
Since statement 2 indicates that the distance between the y-intecepts is 5, lines k and l are not perpendicular.
SUFFICIENT.

The correct answer is D.
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
Post new topic Post Reply
• Page 1 of 1