gmat official guide 13th edition
56th problem.
What is the Value of z in the triangle above?
1. x+y=139 ---> Sufficient x+y+z= 180 substitute x+y
2. y+z=108 ---> x+y+z=180 substitute y+z and u get the value of x then u can rewrite as z=108-y n again substitute it and can get the value of z.
According to the guide the correct answer is A.
please explain why not D..
Data sufficiency help
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To find: "z"
x + y + z = 180*
Statement 1:
x + y = 139
Z = 180 - 139 = 41
SUFFICIENT
Statement 2:
y+z = 108
x = 180-108 = 72
You cannot comment on value of "z"
INSUFFICIENT
Answer [spoiler]{A}[/spoiler]
x + y + z = 180*
Statement 1:
x + y = 139
Z = 180 - 139 = 41
SUFFICIENT
Statement 2:
y+z = 108
x = 180-108 = 72
You cannot comment on value of "z"
INSUFFICIENT
Answer [spoiler]{A}[/spoiler]
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we found out value for "x" & not "y" .. so we cannot do anything by z=108-ysnehavenkat wrote: 2. y+z=108 ---> x+y+z=180 substitute y+z and u get the value of x then u can rewrite as z=108-y n again substitute it and can get the value of z.
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Hi snehavenkat,
In DS questions, when you're asked to find the "value" of something, the question is "really" asking if the value is consistent or inconsistent.
In this DS question, Fact 1 tells you x + y = 139, so if you "plug" that into x + y + z = 180, then you CAN figure out z (it equals 41) and that's the only possible answer. Thus, Fact 1 is SUFFICIENT.
In Fact 2, we're told that y + z = 108
So....there are possibilities....
y = 54, z = 54
y = 53, z = 55
etc.
Thus, z can be different values and there's no way to sure which one it actually is. Thus, Fact 2 is INSUFFICIENT.
GMAT assassins aren't born, they're made,
Rich
In DS questions, when you're asked to find the "value" of something, the question is "really" asking if the value is consistent or inconsistent.
In this DS question, Fact 1 tells you x + y = 139, so if you "plug" that into x + y + z = 180, then you CAN figure out z (it equals 41) and that's the only possible answer. Thus, Fact 1 is SUFFICIENT.
In Fact 2, we're told that y + z = 108
So....there are possibilities....
y = 54, z = 54
y = 53, z = 55
etc.
Thus, z can be different values and there's no way to sure which one it actually is. Thus, Fact 2 is INSUFFICIENT.
GMAT assassins aren't born, they're made,
Rich
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We cannot find z from y + z = 108, hence (2) is not sufficient.snehavenkat wrote:gmat official guide 13th edition
56th problem.
What is the Value of z in the triangle above?
1. x+y=139 ---> Sufficient x+y+z= 180 substitute x+y
2. y+z=108 ---> x+y+z=180 substitute y+z and u get the value of x then u can rewrite as z=108-y n again substitute it and can get the value of z.
According to the guide the correct answer is A.
please explain why not D..
The mind is everything. What you think you become. -Lord Buddha
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com
Thank you so much Rich. Now I found the logic.[email protected] wrote: ↑Tue Oct 22, 2013 12:07 amHi snehavenkat,
In DS questions, when you're asked to find the "value" of something, the question is "really" asking if the value is consistent or inconsistent.
In this DS question, Fact 1 tells you x + y = 139, so if you "plug" that into x + y + z = 180, then you CAN figure out z (it equals 41) and that's the only possible answer. Thus, Fact 1 is SUFFICIENT.
In Fact 2, we're told that y + z = 108
So....there are possibilities....
y = 54, z = 54
y = 53, z = 55
etc.
Thus, z can be different values and there's no way to sure which one it actually is. Thus, Fact 2 is INSUFFICIENT.
GMAT assassins aren't born, they're made,
Rich