y < x + z/2

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y < x + z/2

by tasshy06 » Tue Aug 17, 2010 3:20 am
is y < (x + z)/2?

(1) y-x<z-y
(2) z-y > (z-x)/2

How do i solve this problem??!

Also I attached some screenshots of other GMAT prep questions I'm having trouble with.

Thank you!
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by kmittal82 » Tue Aug 17, 2010 4:09 am
(1)

y -x < z - y

Adding y to both sides

2y - x < z
=> 2y < z + x
=> y < z+x /2 => Sufficient

(2)

z - y > (z -x )/ 2

=> 2z - 2y > z -x
Adding 2y to both sides
=> z + x > 2y
=> z + x /2 > y => Sufficient

Answer should be (D). Can you pls confirm the OA?

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by kvcpk » Tue Aug 17, 2010 4:10 am
tasshy06 wrote:is y < (x + z)/2?

(1) y-x<z-y
(2) z-y > (z-x)/2

How do i solve this problem??!

Also I attached some screenshots of other GMAT prep questions I'm having trouble with.

Thank you!
(1) y-x<z-y
2y<x+z
y<(x+z)/2
SUFF

(2) z-y > (z-x)/2
2z-2y > z-x
z>2y-x
y<(x+z)/2
SUFF

pick D
Last edited by kvcpk on Tue Aug 17, 2010 4:20 am, edited 1 time in total.
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don't be afraid of failure and don't abandon it.
People who work sincerely are the happiest."
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by kmittal82 » Tue Aug 17, 2010 4:19 am
kvcpk wrote:
tasshy06 wrote:is y < (x + z)/2?

(1) y-x<z-y
(2) z-y > (z-x)/2

How do i solve this problem??!

Also I attached some screenshots of other GMAT prep questions I'm having trouble with.

Thank you!
(1) y-x<z-y
2y<x+z
y<(x+z)/2
SUFF

(2) z-y > (z-x)/2
2z-2y > z-x
z>2y+x
y<(z-x)/2
take x=0,y=-1,z=0
-1<0

-1<0+0/2 ..TRUE

take y=-1, x=-2, z= 0
-1<2/2
-1<1

-1<-2/2 -> -1<-1..FALSE

INSUFF

pick A
Hi Kcvpk,

You said:
2z-2y > z-x
z>2y+x


Shouldn't it be:

z > 2y - x ?

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by kvcpk » Tue Aug 17, 2010 4:21 am
kmittal82 wrote: Hi Kcvpk,

You said:
2z-2y > z-x
z>2y+x


Shouldn't it be:

z > 2y - x ?
Yup.. u r ite.. Silly mistake.. edited it. Thanks!!
"Once you start working on something,
don't be afraid of failure and don't abandon it.
People who work sincerely are the happiest."
Chanakya quotes (Indian politician, strategist and writer, 350 BC-275BC)

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by tasshy06 » Tue Aug 17, 2010 6:53 am
the answer is D

thank you for the help!