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

Redeem

gmat sets DS II

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 95
Joined: Wed Mar 10, 2010 3:23 am
Thanked: 1 times
Followed by:1 members

gmat sets DS II

by clammiestqasar » Mon Aug 23, 2010 7:04 am
In the xy-plane, what is the slope of line l?
(1) Line l dose not intersect the line with equation y = 1 - x.
(2) Line l intersects the line with equation y = x - 1.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
Top
Source: — Data Sufficiency |
Senior | Next Rank: 100 Posts
Posts: 50
Joined: Sun Aug 15, 2010 3:00 pm
Thanked: 4 times

by Makushr1 » Mon Aug 23, 2010 7:10 am
clammiestqasar wrote:In the xy-plane, what is the slope of line l?
(1) Line l dose not intersect the line with equation y = 1 - x.
(2) Line l intersects the line with equation y = x - 1.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
Answer is A.

1) The only way for a line to never intersect with another line is it they are parallel.
2) no idea what the slope is, other than it's not y=x-1
Top
Senior | Next Rank: 100 Posts
Posts: 95
Joined: Wed Mar 10, 2010 3:23 am
Thanked: 1 times
Followed by:1 members

by clammiestqasar » Mon Aug 23, 2010 6:17 pm
how can the ans be A if we cannot determine the slope from the given information?
Top
Senior | Next Rank: 100 Posts
Posts: 50
Joined: Sun Aug 15, 2010 3:00 pm
Thanked: 4 times

by Makushr1 » Tue Aug 24, 2010 5:00 am
clammiestqasar wrote:how can the ans be A if we cannot determine the slope from the given information?
If 2 lines on a plane never intersect, they are parallel. So, since A states the line doesn't intersect with another line with the equation y=1-x, line L's equation must also be y=1-x
Top
User avatar
Junior | Next Rank: 30 Posts
Posts: 11
Joined: Wed Aug 11, 2010 1:46 pm

by von » Tue Aug 24, 2010 5:28 am
What's the OA?
Top
Senior | Next Rank: 100 Posts
Posts: 95
Joined: Wed Mar 10, 2010 3:23 am
Thanked: 1 times
Followed by:1 members

by clammiestqasar » Thu Aug 26, 2010 12:59 am
WHy cant the equation be something else?THey are parallel lines and not identical lines?
Top
Legendary Member
Posts: 2326
Joined: Mon Jul 28, 2008 3:54 am
Thanked: 173 times
Followed by:2 members
GMAT Score:710

by gmatmachoman » Thu Aug 26, 2010 1:42 am
Makushr1 wrote:
clammiestqasar wrote:how can the ans be A if we cannot determine the slope from the given information?
If 2 lines on a plane never intersect, they are parallel. So, since A states the line doesn't intersect with another line with the equation y=1-x, line L's equation must also be y=1-x
For parallel lines : m1 = m2

having said that, its not necessary that intercepts are going to be the same:

L1 : y = 3x +3

L2 ; y = 3x + 5

L3: Y = 3x +15

All L1,L2,L3 are parallel , means they wont intersect. They have same slope ( 3) in the above example.

A is sufficient as we can identify the slope.
Top
Senior | Next Rank: 100 Posts
Posts: 50
Joined: Sun Aug 15, 2010 3:00 pm
Thanked: 4 times

by Makushr1 » Thu Aug 26, 2010 4:49 am
clammiestqasar wrote:WHy cant the equation be something else?THey are parallel lines and not identical lines?
They don't have the same intercept, but that itsn't the question. The question is asking if the SLOPE is the same. If 2 lines never intersect on a plane, they must be parallel. Parallel lines have the same slope.
Top
Master | Next Rank: 500 Posts
Posts: 117
Joined: Wed Jun 09, 2010 7:02 am

by missrochelle » Thu Aug 26, 2010 6:25 pm
i think the key point missing here is that if there are 2 lines in an xy plane, they either intersect or are parallel. those are the only two options. if they dont intersect, then they are parallel and have the same slope.
Top
Master | Next Rank: 500 Posts
Posts: 117
Joined: Wed Jun 09, 2010 7:02 am

by missrochelle » Thu Aug 26, 2010 6:26 pm
i think the key point missing here is that if there are 2 lines in an xy plane, they either intersect or are parallel. those are the only two options. if they dont intersect, then they are parallel and have the same slope.
Top
Post new topic Post Reply
• Page 1 of 1