Geometry Qustion... Conceptual.

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Geometry Qustion... Conceptual.

by enjoylife1788 » Fri Oct 28, 2011 10:10 pm
Hey,

I was going through the MGMAT Geometry guide and came across this particular question. Obviously a solution is provided but m not able to follow it. So can someone guide me through it please. I have attached the snapshot of the qustion along with the answer.

Thanks.
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geometry question.png
geometry question
geometry answer.png
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by enjoylife1788 » Fri Oct 28, 2011 10:16 pm
I have understood the way they solved the question. But the question that I have is can we find out the same thing by using pythagorean theorem.

Like the two points are (-5,6) and (-2,0). So we can find the distance between them by using pythagorean, i.e we get (36+9)^1/2. Also the total distance between A and B is 4x. So 4x=(45)^1/2 or 3(5)^1/2. and we find x out of it.

I mean while trying to do this way, the answer doesnt match. So can someone please point out where exactly am I wrong by doing it this way.

Thanx :)

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by shankar.ashwin » Fri Oct 28, 2011 10:45 pm
What you did is correct, but its not what the question asks for. We need not find 'x' here, but we need the co-ordinates of point 'x'.

As you have found 'x' would be Sqrt(45). We know point A(-2,0) Using distance formula, we can find the co-ordinate of the point, and thats what the question asks. But since the values are in decimals that would become too much calculations to do. But yeah you could do that, just that you stopped halfway.

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by enjoylife1788 » Fri Oct 28, 2011 11:14 pm
Thanx for pointing out that they asked for the coordinates and not value of X. I had overlooked it till you pointed it out. I get it now..Thanx a ton :)

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by GMATGuruNY » Sat Oct 29, 2011 3:14 am
enjoylife1788 wrote:Hey,

I was going through the MGMAT Geometry guide and came across this particular question. Obviously a solution is provided but m not able to follow it. So can someone guide me through it please. I have attached the snapshot of the qustion along with the answer.

Thanks.
Please note that the quickest approach might be to use the answer choices, which would be given on the actual GMAT.

Check my solution for the problem here:

https://www.beatthegmat.com/coordinate-g ... 58176.html
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by enjoylife1788 » Sat Oct 29, 2011 9:20 pm
GMATGuruNY wrote:
enjoylife1788 wrote:Hey,

I was going through the MGMAT Geometry guide and came across this particular question. Obviously a solution is provided but m not able to follow it. So can someone guide me through it please. I have attached the snapshot of the qustion along with the answer.

Thanks.
Please note that the quickest approach might be to use the answer choices, which would be given on the actual GMAT.

Check my solution for the problem here:

https://www.beatthegmat.com/coordinate-g ... 58176.html
Thank you for that link. It made me understood much better. Especially the modified weighted average formula, which is applicable here. :)