If KL is parallel to MN, Is x y?

Question

https://gmatclub.com/forum/download/file.php?id=41751 If KL is parallel to MN, Is x> y? (1) KN>LM (2) x and y are larger than 90 degrees gmatbusters.jpg

alldaytestprep · Answer

Imagine to start that NK and ML are perpendicular to the parallel lines. That would mean that they are also the same length. Bending the angles of either line in either direction would then cause the length of that line to increase by a proportional amount since the line would have to stretch to reach the other end. Therefore, simply by knowing the relative lengths of the lines we can deduce information about the relative size of the angles.

1) This tells us that we "bent" KN further than LM however we don't know in which direction. Therefore we don't know if angle x is getting bigger or smaller. 
-----> INSUFFICIENT

2) This tell us NK was "bent" to the right while ML was bent to the "left" but we have no idea by how much
------> INSUFFICIENT

1&2) This tell us NK was "bent" to the right while ML was bent to the "left" + NK bended more than ML. Therefore x>y. 
-----> SUFFICIENT

Answer: C

amanvermagmat · Answer

Hello

I have a doubt here. Isnt it apparent from the figure that we have bent KN to the right and LM to the left. So isnt it quite obvious that both angles x and y are more than 90 degrees. Then why is second statement needed ?

alldaytestprep · Answer

You can't assume images on the GMAT are drawn to scale. For example, there are lots of questions where a triangle that doesn't look like a right triangle ends up being one.

Bunuel · Answer

OFFICIAL GUIDE :

Problem Solving 
 Figures:  All figures accompanying problem solving questions are intended to provide information useful in solving the problems. Figures are drawn as accurately as possible. Exceptions will be clearly noted. Lines shown as straight are straight, and lines that appear jagged are also straight.  The positions of points, angles, regions, etc., exist in the order shown, and angle measures are greater than zero. All figures lie in a plane unless otherwise indicated.

Data Sufficiency: 
 Figures: 
• Figures conform to the information given in the question, but will not necessarily conform to the additional information given in statements (1) and (2).
• Lines shown as straight are straight, and lines that appear jagged are also straight.
• The positions of points, angles, regions, etc., exist in the order shown, and angle measures are greater than zero.
• All figures lie in a plane unless otherwise indicated.

bumpbot · Answer

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If KL is parallel to MN, Is x> y?

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