Lines L and M intersect at (-2,-2). Is the Value of X- intercept of L

Question

Lines L and M intersect at (-2,-2). Is the Value of X- intercept of L greater than that of M?

1) Slope of L is greater than that of M.
2) Slope of L is positive.

Source : Experts Global

Maxximus · Accepted Answer

Hello,

Some confusion here. The OA is E and not A.

Bunuel ,  bb , please change the OA.

Here is the official video explanation-

https://www.youtube.com/watch?v=7AtsCDzL9xI

Thanks
Experts' Global team

srikanth9502 · Answer

If the sign of both the slopes is same, then the X intercept of L is less than that of M. However if L has a positive slope and M has a negative slope, then the X intercept of L is greater than that of M. So A is insufficient.

But the OA mentioned is A and the OE explains the cases in which the sign of both the slopes is same.

ExpertsGlobal ,  Bunuel , or anyone else. Can you pls clear my doubt.

Bunuel · Answer

Edited the OA. Thank you for checking all the questions. Appreciate it.

P.S. You can tag only me in future posts. I'll take care of the edits.

TestPrepUnlimited · Answer

Combined insufficient as shown in the graph below. The problem is if L has a positive slope, M can either have a smaller positive slope or negative slope which completely changes the x-intercept position.

vanam52923 · Answer

I have a samll query 
Stmt A:

If L is parallel to x axis its slope will be zero and if m is negative slope so l>m in slope but my qsn is if line is parallel to x axis so it has y intercept but no x intercept ,so how will this case fit in?or this is absolete case for such option

Kinshook · Answer

Given: Lines L and M intersect at (-2,-2).

Asked: Is the Value of X- intercept of L greater than that of M?

Let Line L be: y+2 = m1 (x+2) = m1x + 2m1; y = m1x + 2m1 -2 (1)
Let Line M be: y+2 = m2 (x+2) = m2x + 2m2; y = m2x + 2m2 -2 (2)

x - intercept of line L : y = 0 = m1x + 2m1 -2 ; x = 2(1-m1)/m1 = 2(1/m1 -1)
x - intercept of line M: y = 0 = m2x + 2m2 -2; x = 2(1-m2)/m2 = 2(1/m2 -1)

1) Slope of L is greater than that of M.
m1 > m2
Since signs of m1 & m2 are unknown
NOT SUFFICIENT

2) Slope of L is positive.
m1>0
Since there is no information about m2.
NOT SUFFICIENT

(1) + (2)
1) Slope of L is greater than that of M.
m1 > m2
Since signs of m1 & m2 are unknown
2) Slope of L is positive.
m1>0
Since sign of m2 is unknown
NOT SUFFICIENT

IMO E

TestPrepUnlimited · Answer

Good question! This problem assumes L must have an x-intercept so we can ignore this special case. Besides that, this only fits in (1) which is insufficient anyways.

azhrhasan · Answer

hi  Kinshook

I am afraid the solution is wrong.

the operation here in statement 1
m1 > m2
1/m1<1/m2

assumes that m1 and m2 are positive .. which may not be the case.

lets say m1=1 and m2=-2, here m1>m2 but 1/m1>1/m2

statement 1 is therefore insufficient.

Kinshook · Answer

azhrhasan

Corrected. Thanks

levin343 · Answer

Sorry this is my curiosity

Understood the M slope is the key here but what about the B - the y-intercept - in a way that even if the slope is the same - say is it correct to say that if the Y-intercept or the B is different, the X intercept also cant be determined?

sagerpbh · Answer

I have some doubt in this question.
First, what is meaning of higher slope. With two negative values of m (y=mx+c), should we consider m with sign or without.
Second, should we consider x intercept with sign or not. 
Please help .

Wizard8 · Answer

Bunuel , please could you answer @sagerpgh question? I have a similar doubt. The question says "Is the Value of X- intercept of L greater than that of M?" Should we not consider sign here? If the x-intercept of a line is -2, would we take +2 or -2 to compare with the value of other slope? Thank you in advance!

Bunuel · Answer

I suggest before attempting questions to brush up the basics.

24. Coordinate Geometry 
     Theory   
 Math: Coordinate Geometry 
 Beauty of Coordinate geometry 
 Dealing with Tangents on the GMAT 
     Questions   
 DS Questions 
 PS Questions

For more check  Ultimate GMAT Quantitative Megathread

Hope it helps.

suryamunjal1582 · Answer

the answer should be A as in case when L has a positive slope and M has a negative slope, then the magintude of = X intercept of M is greater than that of L. So A should be sufficient . when we are talking about intercept , we only see magnitude not the sign of intercept . So i feel answer A should be correct

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

Lines L and M intersect at (-2,-2). Is the Value of X- intercept of L

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Data Sufficiency (DS) Questions

Lines L and M intersect at (-2,-2). Is the Value of X- intercept of L

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards