Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Nov 2007:30 AM PST
-08:30 AM PST
Learn what truly sets the UC Riverside MBA apart and how it helps in your professional growth
Nov 2211:00 AM IST
-01:00 PM IST
Do RC/MSR passages scare you? e-GMAT is conducting a masterclass to help you learn – Learn effective reading strategies Tackle difficult RC & MSR with confidence Excel in timed test environment- Nov 23
11:00 AM IST
-01:00 PM IST
Attend this free GMAT Algebra Webinar and learn how to master the most challenging Inequalities and Absolute Value problems with ease. 
Nov 2510:00 AM EST
-11:00 AM EST
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors.
B
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
15%
(low)
Question Stats:
84% (01:38) correct
16%
(01:34)
wrong
based on 218
sessions
History
Date
Time
Result
Not Attempted Yet
Points X, Y, and Z are located on the rectangular coordinate plane at points (2; 3), (-4; 3), and (2; -3), respectively. What is the length of line segment YZ?
A. 6
B. 6*root(2)
C. 7
D. 8
E. 9
My Q is why cant we use the distance formula for Y / Z and get the length = 6
A. 6
B. 6*root(2)
C. 7
D. 8
E. 9
The OA = B 6*root(2)
My Q is why cant we use the distance formula for Y / Z and get the length = 6
14 Feb 2012, 06:22
Kudos
Bookmarks
Well of course you can use the distance formula but do realize that the distance formula is not really covered by the Original Guide. Hence, they had to provide a 3rd coordinate to make it a right angled triangle so that you could use the pythagorus theorem. Using the distance formula:
For 2 points: A & B, Distance between A and B \(=\sqrt{({(x_1-x_2)}^2 + {(y_1-y_2)}^2)}\)
Where \(A=(x_1,y_1)\) & \(B=(x_2,y_2)\)
In the question above \(Y=(-4,3)\) & \(Z=(2,-3)\)
Distance between 2 points, Y & Z, on the coordinate system \(=\sqrt{({(-4-2)}^2 + {(3+3)}^2)}\)
Which is \(=\sqrt{(6^2 + 6^2)}\)
Which is \(=\sqrt{72}\)
Which is \(=6\sqrt{2}\)
So Yes, to answer your question, info about \(Y\) & \(Z\) alone is sufficient "if you know the formula for deriving the distance between two coordinates", but otherwise you need to know a third point to first establish it is a right angled triangle. Works either ways. I have seen numerous statistics questions where GMAT actually gives you the formula for calculating the sum of the series, even though we need to know it to solve quite a few question on the GMAT. Either ways, your pick. Answer still remains the same \(=6\sqrt{2}\) and not \(6\)!
For 2 points: A & B, Distance between A and B \(=\sqrt{({(x_1-x_2)}^2 + {(y_1-y_2)}^2)}\)
Where \(A=(x_1,y_1)\) & \(B=(x_2,y_2)\)
In the question above \(Y=(-4,3)\) & \(Z=(2,-3)\)
Distance between 2 points, Y & Z, on the coordinate system \(=\sqrt{({(-4-2)}^2 + {(3+3)}^2)}\)
Which is \(=\sqrt{(6^2 + 6^2)}\)
Which is \(=\sqrt{72}\)
Which is \(=6\sqrt{2}\)
So Yes, to answer your question, info about \(Y\) & \(Z\) alone is sufficient "if you know the formula for deriving the distance between two coordinates", but otherwise you need to know a third point to first establish it is a right angled triangle. Works either ways. I have seen numerous statistics questions where GMAT actually gives you the formula for calculating the sum of the series, even though we need to know it to solve quite a few question on the GMAT. Either ways, your pick. Answer still remains the same \(=6\sqrt{2}\) and not \(6\)!
14 Feb 2012, 06:58
Kudos
Bookmarks
rxs0005
You can use the distance formula to calculate the length of line segment YZ
The formula to calculate the distance between two points \((x_1,y_1)\) and \((x_2,y_2)\) is \(d=\sqrt{(x_1-x_2)^2+(y_1-y_2)^2}\).
Thus \(YZ=\sqrt{(-4-2)^2+(3-(-3))^2}=6\sqrt{2}\).
Answer: B.
If you are not aware of this formula then you can easily get the answer by drawing the triangle:
Attachment:
xy-plane.PNG [ 15.5 KiB | Viewed 6452 times ]
Answer: B.
For more on Coordinate Geometry check: math-coordinate-geometry-87652.html
Hope it helps.
