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

Redeem

MGMAT co-ordinate geometry

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 105
Joined: Tue Oct 16, 2007 5:57 am
Thanked: 3 times

MGMAT co-ordinate geometry

by abhi75 » Mon Mar 17, 2008 8:47 am
Line l is defined by the equation y – 5x = 4 and line w is defined by the equation 10y + 2x + 20 = 0. If line k does not intersect line l, what is the degree measure of the angle formed by line k and line w?

0
30
60
90
It cannot be determined from the information given.

This is another problem where I dont get the solution provided by MGMAT. The answer is not e.

Can someone please explain it.

Answer is D.
Top
Source: — Problem Solving |
Legendary Member
Posts: 645
Joined: Wed Sep 05, 2007 4:37 am
Location: India
Thanked: 34 times
Followed by:5 members

Re: MGMAT co-ordinate geometry

by camitava » Mon Mar 17, 2008 9:52 am
abhi75 wrote:Line l is defined by the equation y – 5x = 4 and line w is defined by the equation 10y + 2x + 20 = 0. If line k does not intersect line l, what is the degree measure of the angle formed by line k and line w?

0
30
60
90
It cannot be determined from the information given.

This is another problem where I dont get the solution provided by MGMAT. The answer is not e.

Can someone please explain it.

Answer is D.
Abhi, refer the point - line k and line l are not intersecting at all. So these lines have to be parallel. If so slope of k = 5 ->Got it Abhi?
Again slope of line w = -2/10 = -1/5
Now slope of k * slope of w = -1
So they are perpendicular to each other.
So the angle is 90. So IMO D. Got my response, Abhi?
Correct me If I am wrong


Regards,

Amitava
Top
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Mon Jan 14, 2008 6:37 am

by Kekela » Tue Mar 18, 2008 1:35 am
camitiva,

can you explain this:

Now slope of k * slope of w = -1
So they are perpendicular to each other.
Top
Legendary Member
Posts: 645
Joined: Wed Sep 05, 2007 4:37 am
Location: India
Thanked: 34 times
Followed by:5 members

by camitava » Tue Mar 18, 2008 2:54 am
Kekela wrote:camitiva,

can you explain this:

Now slope of k * slope of w = -1
So they are perpendicular to each other.
Kekela, I would like to say - please go thru the tutorials provided by GMATPrep s/w or do some google search. The point I mentioned earlier, is a basic co-ordinate geometry principle.
Correct me If I am wrong


Regards,

Amitava
Top
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Mon Jan 14, 2008 6:37 am

by Kekela » Tue Mar 18, 2008 3:28 am
ok, thanks!
Top
Newbie | Next Rank: 10 Posts
Posts: 1
Joined: Mon Mar 24, 2008 4:02 pm

Re: MGMAT co-ordinate geometry

by rbhavikatti » Mon Mar 31, 2008 1:48 pm
camitava wrote:
abhi75 wrote:Line l is defined by the equation y – 5x = 4 and line w is defined by the equation 10y + 2x + 20 = 0. If line k does not intersect line l, what is the degree measure of the angle formed by line k and line w?

0
30
60
90
It cannot be determined from the information given.

This is another problem where I dont get the solution provided by MGMAT. The answer is not e.

Can someone please explain it.

Answer is D.
Abhi, refer the point - line k and line l are not intersecting at all. So these lines have to be parallel. If so slope of k = 5 ->Got it Abhi?
Again slope of line w = -2/10 = -1/5
Now slope of k * slope of w = -1
So they are perpendicular to each other.
So the angle is 90. So IMO D. Got my response, Abhi?

But the question says, two lines never intersect, then where is this measure of angle betwwen them come from????
Top
Master | Next Rank: 500 Posts
Posts: 111
Joined: Thu Jan 31, 2008 4:05 pm
Thanked: 18 times
Followed by:1 members

by xilef » Mon Mar 31, 2008 2:20 pm
rbhavikatti,
it says 'line k does not intersect line l...' and asks for the measurement of the angle formed by line K and line W. Please read the question carefully before posting.
Top
Legendary Member
Posts: 789
Joined: Sun May 06, 2007 1:25 am
Location: Southern California, USA
Thanked: 15 times
Followed by:6 members

ok

by resilient » Mon Mar 31, 2008 7:06 pm
I can see your point for the confusion. Can you notice that the slopes of l and w are negative reciprocals. TO help ease all confusion, make sure to map out or draw out as much as possible. THis will give you more clarity!
Appetite for 700 and I scraped my plate!
Top
Post new topic Post Reply
• Page 1 of 1