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In the xyplane, what is the yintercept of line l? [#permalink]
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28 Feb 2010, 20:51
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In the xyplane, what is the yintercept of line l? (1) The slope of line l is 3 times its yintercept (2) The xintercept of line l is 1/3
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Re: GMATPrep: yintercept [#permalink]
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01 Mar 2010, 01:42
testprep2010 wrote: Source: GMATPrep Please solve this question (with explanation): In the xyplane, what is the yintercept of line l? 1. The slope of line l is 3 times its yintercept 2. The xintercept of line l is 1/3 Equation of a line in point intercept form is \(y=mx+b\), where: \(m\) is the slope of the line; \(b\) is the yintercept of the line (the value of \(y\) for \(x=0\)); \(x\) is the independent variable of the function \(y\). The question is \(b=?\) (1) The slope of line l is 3 times its yintercept > \(m=3b\). Not sufficient to calculate \(b\). (2) The xintercept of line l is 1/3 > xintercept is the value of \(x\) for \(y=0\) > \(0=\frac{1}{3}m+b\) > \(m=3b\). Same info as above. Not sufficient. (1)+(2) Nothing new. Not sufficient. For more on this issue please check Coordinate Geometry chapter of Math Book (link in my signature). Hope it helps.
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Re: GMAT PREP DS [#permalink]
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23 Aug 2010, 19:47
uzzy12 wrote: In the xyplane, what is the yintercept of line l?
(1) The slope of line l is 3 itmes the yintercept (2) The xintercept of line l is 1/3 My attempt: Line equation  y = mx +c We need the value of c which the yintercept of the line. Statement 1: Slope is 3 times the y intercept. Hence dy/ dx = 3c. or m = 3c or c = m/3. Without m we cannot identify the value of c. Insufficient. Statement 2: X intercept of the line is 1/3. X intercept => 0 = m*x+c 0 = m (1/3) + c c = (1/3) * m. Without m, we cannot determine c. Insufficient. Combining both (1) and (2), we know m = 3c and c = (1/3)m and both are the same. No way to identify c. Hence insufficient. Answer E.
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Re: What is the yintercept of the line [#permalink]
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18 Sep 2010, 15:26
To find: yintercept of the line. When the line intercepts the y axis, x=0. Hence the original equation y=mx+c becomes y=c. Question asks for the value of c. Statement 1: Slope of the line is 3 times the y intercept. Hence m = 3c. Insufficient. Statement 2: The x intercept is 1/3. x intercept means y is zero. Hence the original line equation becomes 0=m(1/3) +c m = 3c. Same as the first equation. Insufficient. Combining both yields nothing. Hence the answer is E.
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Re: What is the yintercept of the line [#permalink]
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18 Sep 2010, 16:09
\(y=mx+c\) m > Slope c > Yint This may be rewritten as : \(\frac{x}{c/m} + \frac{y}{c} = 1\) We know that in terms of intercept the equation of the line is : \(\frac{x}{XInt} + \frac{y}{YInt} = 1\) So \(XInt = c/m, YInt = c\) (1)m=3c ... Not enough to say what the value of c is (2)c/m = 1/3 .... Hence m=3c. We know this is not sufficient (1)+(2) : Same as (1) or (2) Hence, answer is {e} ...neither statement enough
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Re: Coordinate geometry [#permalink]
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08 Jan 2012, 03:11
Let the eqn of line be y=mx+c To get yintercept x=0 i.e. y=c ?
1) m = 3c Insuff.
2) 0 =  m/3 + c or c= m/3 Insuff. (Same as stmt 1)
Hence E



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Re: Coordinate geometry [#permalink]
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08 Jan 2012, 18:57
Rephrase: y = mx+c, c=? 1. m=3c. y=3cx+c, insuff 2. 0=1/3m+c, c= m/3. insuff. Both equations unsolvable. insuff. E
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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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09 Dec 2012, 18:32
I approached this problem as: y = mx + c.....equation of line... (1)
to find C
1) m = 3c.... (2)
substitute (2) in (1)
y = 3cx + c y = c(3x +1)...... (3)
2) X intercept = 1/3
2 implies the line passes through (1/3,0) doesnt give enough info for M
Combined substitute point (1/3,0) in (3)
0 = c(3 * 1/3 +1) 0 = c (1+1 ) c = 0 ?
what did i do wrong ?



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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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10 Dec 2012, 01:41



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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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30 Sep 2013, 12:35
testprep2010 wrote: In the xyplane, what is the yintercept of line l?
(1) The slope of line l is 3 times its yintercept (2) The xintercept of line l is 1/3 1. y=mx+c given >> m=3c y=3cx+c when y=0, x=1/3 .. from point 1/3,0 we can draw 2 lines satisfying the condition given above, one with obtuse angle(ve y intercept) and other with acute angle(+ve y intercept) .. hence, not sufficient 2. x=1/3 we can draw infinite lines passing from this point .. very clear ..
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Re: GMATPrep: yintercept [#permalink]
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31 Mar 2014, 23:31
Bunuel wrote: testprep2010 wrote: Source: GMATPrep Please solve this question (with explanation): In the xyplane, what is the yintercept of line l? 1. The slope of line l is 3 times its yintercept 2. The xintercept of line l is 1/3 Equation of a line in point intercept form is \(y=mx+b\), where: \(m\) is the slope of the line; \(b\) is the yintercept of the line (the value of \(y\) for \(x=0\)); \(x\) is the independent variable of the function \(y\). The question is \(b=?\) (1) The slope of line l is 3 times its yintercept > \(m=3b\). Not sufficient to calculate \(b\). (2) The xintercept of line l is 1/3 > xintercept is the value of \(x\) for \(y=0\) > \(0=\frac{1}{3}m+b\) > \(m=3b\). Same info as above. Not sufficient. (1)+(2) Nothing new. Not sufficient. For more on this issue please check Coordinate Geometry chapter of Math Book (link in my signature). Hope it helps. Hi Bunuel, In every DS question, if both statements provide the exact same insufficient information and that information is derived in different ways ( slope in (1) and xintercept in (2) ) , can we assume that both together are insufficient?



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Re: GMATPrep: yintercept [#permalink]
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01 Apr 2014, 00:01
TooLong150 wrote: Bunuel wrote: testprep2010 wrote: Source: GMATPrep Please solve this question (with explanation): In the xyplane, what is the yintercept of line l? 1. The slope of line l is 3 times its yintercept 2. The xintercept of line l is 1/3 Equation of a line in point intercept form is \(y=mx+b\), where: \(m\) is the slope of the line; \(b\) is the yintercept of the line (the value of \(y\) for \(x=0\)); \(x\) is the independent variable of the function \(y\). The question is \(b=?\) (1) The slope of line l is 3 times its yintercept > \(m=3b\). Not sufficient to calculate \(b\). (2) The xintercept of line l is 1/3 > xintercept is the value of \(x\) for \(y=0\) > \(0=\frac{1}{3}m+b\) > \(m=3b\). Same info as above. Not sufficient. (1)+(2) Nothing new. Not sufficient. For more on this issue please check Coordinate Geometry chapter of Math Book (link in my signature). Hope it helps. Hi Bunuel, In every DS question, if both statements provide the exact same insufficient information and that information is derived in different ways ( slope in (1) and xintercept in (2) ) , can we assume that both together are insufficient? Hi Toolong150, Do not assume anything on DS question unless and until it is obvious. To your above question, If you get same insufficient information from both statements then ans is E as is above the case. If you look at the above question,actually both statement tell you the same thing but in st1 it talks about slope and st 2 it talks about x intercept St 1 y= mx+ c says m =3c now if you find x intercept (y=0) we get 0=3cx+c or x=1/3 Same as st 2 Hope it helps
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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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30 Nov 2014, 15:47
Bunuel wrote: testprep2010 wrote: Source: GMATPrep Please solve this question (with explanation): In the xyplane, what is the yintercept of line l? 1. The slope of line l is 3 times its yintercept 2. The xintercept of line l is 1/3 Equation of a line in point intercept form is \(y=mx+b\), where: \(m\) is the slope of the line; \(b\) is the yintercept of the line (the value of \(y\) for \(x=0\)); \(x\) is the independent variable of the function \(y\). The question is \(b=?\) (1) The slope of line l is 3 times its yintercept > \(m=3b\). Not sufficient to calculate \(b\). (2) The xintercept of line l is 1/3 > xintercept is the value of \(x\) for \(y=0\) > \(0=\frac{1}{3}m+b\) > \(m=3b\). Same info as above. Not sufficient. (1)+(2) Nothing new. Not sufficient. For more on this issue please check Coordinate Geometry chapter of Math Book (link in my signature). Hope it helps. Hi Bunuel, I realize that "b' is the y intercept in the equation y = mx + b. That being said, I was a little confused as to whether I should solve for B or solve for Y by equation x to 0. If I did the latter, i would get y = b. How do I know I I should plug in values for X and Y or solve for B? This part seems to give me the most trouble. Thanks



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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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01 Dec 2014, 05:39
russ9 wrote: Bunuel wrote: testprep2010 wrote: Source: GMATPrep Please solve this question (with explanation): In the xyplane, what is the yintercept of line l? 1. The slope of line l is 3 times its yintercept 2. The xintercept of line l is 1/3 Equation of a line in point intercept form is \(y=mx+b\), where: \(m\) is the slope of the line; \(b\) is the yintercept of the line (the value of \(y\) for \(x=0\)); \(x\) is the independent variable of the function \(y\). The question is \(b=?\) (1) The slope of line l is 3 times its yintercept > \(m=3b\). Not sufficient to calculate \(b\). (2) The xintercept of line l is 1/3 > xintercept is the value of \(x\) for \(y=0\) > \(0=\frac{1}{3}m+b\) > \(m=3b\). Same info as above. Not sufficient. (1)+(2) Nothing new. Not sufficient. For more on this issue please check Coordinate Geometry chapter of Math Book (link in my signature). Hope it helps. Hi Bunuel, I realize that "b' is the y intercept in the equation y = mx + b. That being said, I was a little confused as to whether I should solve for B or solve for Y by equation x to 0. If I did the latter, i would get y = b. How do I know I I should plug in values for X and Y or solve for B? This part seems to give me the most trouble. Thanks y = b cannot be sufficient. When a DS question asks about the value of some variable, then the statement(s) is sufficient ONLY if you can get the single numerical value of this variable. Hope it's clear.
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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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20 Feb 2016, 02:29
Bunuel: can you suggest similar questions? Thanks



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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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22 Feb 2016, 01:18



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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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24 Jul 2016, 14:22
Isn't C true because the equation is y = 3x + 1? Making the y intercept 1. I don't see how it can be any other equation..
I don't see any other equation that will satisfy both of those statements?



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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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24 Jul 2016, 22:08



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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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01 Feb 2017, 17:12
If the slope and yintercept of a line in xy plane are m and c respectively, then the line can be represented by the equation y = mx + c and the x=intercept of the line will be c/m Statement 1: m = 3c > Not sufficient Statement 2: c/m = 1/3 > m = 3c > Not sufficient 1 & 2 Together: We have no new information > Not sufficient hence E
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Re: In the xyplane, what is the yintercept of line l? [#permalink]
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06 May 2017, 12:23
stunn3r wrote: testprep2010 wrote: In the xyplane, what is the yintercept of line l?
(1) The slope of line l is 3 times its yintercept (2) The xintercept of line l is 1/3 1. y=mx+c given >> m=3c y=3cx+c when y=0, x=1/3 .. from point 1/3,0 we can draw 2 lines satisfying the condition given above, one with obtuse angle(ve y intercept) and other with acute angle(+ve y intercept) .. hence, not sufficient 2. x=1/3 we can draw infinite lines passing from this point .. very clear .. Can you elaborate on your reasoning for 2). Not any line would suffice, would it? The line would still have to have m=3c.




Re: In the xyplane, what is the yintercept of line l?
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