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GMAT PAPER TEST DS

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GMAT PAPER TEST DS

by smclean23 » Sun Dec 28, 2008 12:14 pm
Are all the numbers in a certain list of 15 numbers equal?

1) The sum of all the numbers in the list is 60.

2) The sum of any 3 numbers in the list is 12.



OA is B..............Couldn't the sum of any 3 numbers be 4+4+4, 1+2+9, 0+1+11.....There is no indication that 0 is not considered a number. I think I am not reading something correctly. Please advise.
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Source: — Data Sufficiency |
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by cramya » Sun Dec 28, 2008 12:28 pm
OA is B..............Couldn't the sum of any 3 numbers be 4+4+4, 1+2+9, 0+1+11.....There is no indication that 0 is not considered a number. I think I am not reading something correctly. Please advise
The sum of any 3 numbers is 12 (this means if u pick any three numbers in the list then the sum should be or is 12

From your example 1+2+9, 0+1+11 - > TRUE

but 1 +2 + 11 is not 12

Hope this helps!
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by vittalgmat » Sun Dec 28, 2008 7:02 pm
Quick clue: whenever u see a statement like "sum of any x numbers in the set is y", u can almost be sure that all the numbers are the same and will probably be = y/x.

This is a very big restriction imposed on the set and kind of makes the set "well behaved" (kind of forcing all the naughty kids to walk in a single file)

HT Helps
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by vivek.kapoor83 » Mon Dec 29, 2008 10:26 am
i couldnt get it ...pls solve it Crmaya,vittal..
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by cramya » Mon Dec 29, 2008 10:30 am
Stmt I

Sum of 15 numbers is 60

4 repeated 14 times then 1 and 3 - sum 60 numbers not equal -NO

4 repeated 15 times -All numbers are equal YES

INSUFF

Stmt II

The sum of any three numbers is 12. The only way this is possible is if all numbers are 4. If u pick any other number in the list sum of any 3 numbers will not be 12

Sum of any 3 means no matter which 3 u pick the sum must be 12. It is easy to confuse this with sum of just 3 numbers u pick from the list is 12 and the rest not.

SUFF

Choose B)
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