Must be C
The question really asks whether lines l and l are perpendicular? The product of slopes of Perpendicular lines are always -1.
1. No info about line k. Insufficient.
2. No info about line l. Insufficient.
Combined,
Line K has a slope of 2 (m1) [Points are (0,0) and (1,2). Slope = 2-0 / 1-2 = 2]
Line L has a slope of -1/2 (m2) [Equation of the line is 2x+4y=8. Slope = -2/4 = -1/2]
m1 * m2 = 2 * -1/2 = -1 (Lines are perpendicular)
Sufficient.
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Source: Beat The GMAT — Data Sufficiency |
yeah.papgust wrote:Must be C
what a ... strange question.
The question really asks whether lines l and l are perpendicular? The product of slopes of Perpendicular lines are always -1.
1. No info about line k. Insufficient.
2. No info about line l. Insufficient.
so far so good.
totally unnecessary work. don't waste your time.Combined,
Line K has a slope of 2 (m1) [Points are (0,0) and (1,2). Slope = 2-0 / 1-2 = 2]
Line L has a slope of -1/2 (m2) [Equation of the line is 2x+4y=8. Slope = -2/4 = -1/2]
m1 * m2 = 2 * -1/2 = -1 (Lines are perpendicular)
Sufficient.
here's all you have to do:
* statement (1): there is EXACTLY ONE LINE that does this.
* statement (2): there is EXACTLY ONE LINE that does this.
* so, if you have them together, IT'S EITHER "YES" OR "NO".
sufficient.
done.
TAKEAWAY:
DO NOT GET YOUR HEAD STUCK IN "PROBLEM SOLVING MODE" WHEN YOU WORK DATA SUFFICIENCY PROBLEMS.
remember - a lot of computation is unnecessary when you're doing a DS problem. if you know that you CAN get an answer, that's all you need - there is no reason at all to spend time going through the steps.
Ron has been teaching various standardized tests for 20 years.
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Pueden hacerle preguntas a Ron en castellano
Potete chiedere domande a Ron in italiano
On peut poser des questions à Ron en français
Voit esittää kysymyksiä Ron:lle myös suomeksi
--
Quand on se sent bien dans un vêtement, tout peut arriver. Un bon vêtement, c'est un passeport pour le bonheur.
Yves Saint-Laurent
--
Learn more about ron
Hey Ron,
Even i'm aware that the computations are unnecessary. I just wanted to detail the concept behind it for the question poster. Probably, i should have mentioned in the end clearly that these steps are unnecessary and i just intended to explain the concept.
Even i'm aware that the computations are unnecessary. I just wanted to detail the concept behind it for the question poster. Probably, i should have mentioned in the end clearly that these steps are unnecessary and i just intended to explain the concept.
papgust wrote:Must be C
The question really asks whether lines l and l are perpendicular? The product of slopes of Perpendicular lines are always -1.
1. No info about line k. Insufficient.
2. No info about line l. Insufficient.
Combined,
Line K has a slope of 2 (m1) [Points are (0,0) and (1,2). Slope = 2-0 / 1-2 = 2]
Line L has a slope of -1/2 (m2) [Equation of the line is 2x+4y=8. Slope = -2/4 = -1/2]
m1 * m2 = 2 * -1/2 = -1 (Lines are perpendicular)
Sufficient.
can you please tell me how did you figure out that for line L has slope = -1/2? we are given x-intercept and y-intercept. how did you derive slope from the two intercepts?
thanks
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thephoenix
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x inter cept is 4 means its coordinates are 4,0(x1,y1)shahab03 wrote:papgust wrote:Must be C
The question really asks whether lines l and l are perpendicular? The product of slopes of Perpendicular lines are always -1.
1. No info about line k. Insufficient.
2. No info about line l. Insufficient.
Combined,
Line K has a slope of 2 (m1) [Points are (0,0) and (1,2). Slope = 2-0 / 1-2 = 2]
Line L has a slope of -1/2 (m2) [Equation of the line is 2x+4y=8. Slope = -2/4 = -1/2]
m1 * m2 = 2 * -1/2 = -1 (Lines are perpendicular)
Sufficient.
can you please tell me how did you figure out that for line L has slope = -1/2? we are given x-intercept and y-intercept. how did you derive slope from the two intercepts?
thanks
and y intercept is 2 means its coorniates are 0,2(x2,y2)
slope m=(y2-y1)/(x2-x1)----->(2-0)/(0-4)=-1/2
hth
