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Is x+y<1 : GMAT Prep

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Khalid
 Post subject: Is x+y<1 : GMAT Prep
 Post Posted: Sun Dec 28, 2008 1:43 pm 
Is x+y <1

1) x <8/9
2) x < 1/8

OA E

This is what I did:

X < 8/9
+ X < 1/8
_________
= X < 73/72

Since statement both the fractions then are supposed to be less than 8/9 and 1/8 respectively, I assumed that what I calculated were the outliers. So I picked C.

Since GMAT is never wrong - I am sure I am. Can anyone please explain where I went wrong?

Thanks, Khalid
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lilpetunia
 Post subject: ???
 Post Posted: Mon Dec 29, 2008 11:06 am 
this problem makes no sense. Regardless how much info you have about x, the answer is E if you have no info about y.
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Khalid
 Post subject: Re: ???
 Post Posted: Mon Dec 29, 2008 11:52 am 
lilpetunia wrote:
this problem makes no sense. Regardless how much info you have about x, the answer is E if you have no info about y.


Sorry, typo on my part:

1) X < 8/9
2) Y < 1/8

Thanks
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Live Stronger
 Post subject: Re: Is x+y<1 : GMAT Prep
 Post Posted: Mon Dec 29, 2008 12:13 pm 
Khalid wrote:
Is x+y <1

1) x <8/9
2) Y < 1/8

OA E

This is what I did:

X < 8/9
+ Y < 1/8
_________
= X+Y < 73/72

Since statement both the fractions then are supposed to be less than 8/9 and 1/8 respectively, I assumed that what I calculated were the outliers. So I picked C.

Since GMAT is never wrong - I am sure I am. Can anyone please explain where I went wrong?

Thanks, Khalid


I fixed the typo.

You did the right thing.
But when x+y<73/72, it could mean that x+y = 72/72 = 1 or x+y = 36/72 = 0.5
So. it can't be said for sure that x+y < 1, and that why the answer is E
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JonathanSchneider
 Post subject:
 Post Posted: Mon Jan 05, 2009 2:01 pm 
Offline
ManhattanGMAT Staff


Posts: 380
Good catch, and good explanation above. Answer is E.
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