Last visit was: 20 Nov 2025, 06:22 It is currently 20 Nov 2025, 06:22
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
kirankp
Joined: 22 Jul 2008
Last visit: 25 Sep 2012
Posts: 58
Own Kudos:
1,326
 [18]
Given Kudos: 11
Location: Bangalore,Karnataka
Posts: 58
Kudos: 1,326
 [18]
2
Kudos
Add Kudos
16
Bookmarks
Bookmark this Post
Most Helpful Reply
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 20 Nov 2025
Posts: 105,416
Own Kudos:
Given Kudos: 99,987
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 105,416
Kudos: 778,504
 [12]
7
Kudos
Add Kudos
5
Bookmarks
Bookmark this Post
General Discussion
User avatar
chetan2u
User avatar
GMAT Expert
Joined: 02 Aug 2009
Last visit: 15 Nov 2025
Posts: 11,238
Own Kudos:
Given Kudos: 335
Status:Math and DI Expert
Location: India
Concentration: Human Resources, General Management
GMAT Focus 1: 735 Q90 V89 DI81
Products:
Expert
Expert reply
GMAT Focus 1: 735 Q90 V89 DI81
Posts: 11,238
Kudos: 43,709
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
udaymathapati
Joined: 06 Apr 2010
Last visit: 27 Jan 2015
Posts: 91
Own Kudos:
5,543
 [2]
Given Kudos: 15
Products:
Posts: 91
Kudos: 5,543
 [2]
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
In the xy-plane, line l and line k intersect at the point (16/5, 12/5). What is the slope of line l?

(1) The product of the slopes of line l and line k is –1.
(2) Line k passes through the origin.
User avatar
jpr200012
Joined: 30 May 2010
Last visit: 10 Oct 2011
Posts: 137
Own Kudos:
835
 [1]
Given Kudos: 32
Posts: 137
Kudos: 835
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
We know one point in the coordinate system.

(1) Insufficient. First, you must know that perpendicular lines have negative reciprocal slopes. We know that the product of the slopes of l and k is -1, therefore they are perpendicular.

(2) Insufficient. We can now solve for the slope of k, but we know nothing about l.

(1+2) Sufficient, Since we know the slope of k, then we know the slope of l is -1/k.
User avatar
jpr200012
Joined: 30 May 2010
Last visit: 10 Oct 2011
Posts: 137
Own Kudos:
Given Kudos: 32
Posts: 137
Kudos: 835
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Bunuel, you are too quick!
User avatar
BlitzHN
Joined: 07 Aug 2010
Last visit: 26 May 2011
Posts: 33
Own Kudos:
Given Kudos: 9
Posts: 33
Kudos: 24
Kudos
Add Kudos
Bookmarks
Bookmark this Post
C

1) says l and k have opposite slopes. so given point is perpendicular point on intersection ==> NOT SUFF though to find the slope

2) point of intersection and origin will give us the slope of k ==> NOT SUFF by itself since we would not know about the perpendicular bisection

1 + 2 ==> -1/slope of k == slope of l ==> SUFF
User avatar
0ld
Joined: 24 Aug 2016
Last visit: 09 Apr 2017
Posts: 48
Own Kudos:
82
 [4]
Given Kudos: 24
Location: India
WE:Information Technology (Computer Software)
Posts: 48
Kudos: 82
 [4]
3
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Let equation of line l --> \(y = Lx + a\)
Let equation of line K --> \(y = Kx + b\)

Both line passes through (16/5, 12/5)

\(16L+5a = 12\) --Eq 1
\(16K+5b = 12\) --Eq2

(1) The product of the slopes of line l and line k is –1.

\(L * K=-1\) --Eq3

We have 3 equation and 4 unknown (a,b,L, M). -- Not sufficient

(2) Line k passes through the origin.

\(b = 0\)
\(16K+5b = 12\) ==> \(16K= 12\) ==> \(\frac{3}{4}\) -- Not sufficient


When we combine (1) and (2), L = -\(\frac{4}{3}\) --Sufficient.

Ans C.
User avatar
Kimberly77
Joined: 16 Nov 2021
Last visit: 07 Sep 2024
Posts: 435
Own Kudos:
45
 [1]
Given Kudos: 5,898
Location: United Kingdom
GMAT 1: 450 Q42 V34
Products:
GMAT 1: 450 Q42 V34
Posts: 435
Kudos: 45
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi brunel, line l and line k intersect at the point (16/5, 12/5) as stated in question, therefore doesn't this show relation between line l and line k in statement 2?
or am I missing something? Thanks
User avatar
bumpbot
User avatar
Non-Human User
Joined: 09 Sep 2013
Last visit: 04 Jan 2021
Posts: 38,598
Own Kudos:
Posts: 38,598
Kudos: 1,079
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Moderators:
Math Expert
105416 posts
496 posts