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elements in Set A, B and C

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elements in Set A, B and C

by nirajanshrestha » Mon Dec 14, 2009 5:48 am
Set A, B and C have some elements in common. If 16 elements are in both A and B, 17 elements are in both A and C, and 18 elements are in both B and C, how many elements do all these three of the sets A, B and C have in common?

1. Of the 16 elements that are both in A and B, 9 elements are also in C.
2. A has 25 elements, B has 30 elements and C has 35 elements.
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by punitkaur » Mon Dec 14, 2009 11:37 am
IMO A.

1. right away gives A & B & C = 7 - sufficient

2. For this one we need the total no of elements in A,B,C (A U B U C) to calculate A&B&C. - not sufficient
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by mehravikas » Mon Dec 14, 2009 7:18 pm
I am not too sure - Can we rule out B for the following reasons:

1. It doesn't give the total number of elements
2. It doesn't give the elements that do not belong to A, B and C.
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by hamxa » Thu Mar 11, 2010 3:30 am
@ punitkaur

You mean 9 elements in common ?
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by blaster » Thu Mar 11, 2010 4:58 am
I think IMO is E .
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by hamxa » Thu Mar 11, 2010 8:15 am
the solution by punitkar is on the right lines

this is from gmatprep and OA is A.
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by outreach » Thu Mar 11, 2010 10:37 am
Total = Group1 + Group2 + Group3 - (sum of 2-group overlaps) - 2*(all three) + Neither

opt 1:
all 3 is 9. Sufficient.

opt 2:
Gives us Group1 Group2 & Group3. Unless we know 'Total' and 'neither' this info is useless. Insuff
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by girish3131 » Tue Mar 16, 2010 12:22 am
I do not agree at all that A is right ans....

Even if u consider 9 are common among A, B and C

still we dont have any clue that

whether

elements which are common b/w B and C also common with A also.... ?

and

whether

elements which are common b/w C and A also common with B too... ?

without these inf... nothing can be said....


IMO Ans is E
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by STEVEN SPIELBERG » Tue Mar 16, 2010 2:01 am
What's the OA ?
I want to win an OSCAR on the GMAT !!!
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by sarthak » Tue Mar 16, 2010 5:11 am
OA is A
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by cooo3 » Fri Mar 19, 2010 3:31 am
i agree with girish.

can you please explain why you chose A ?

IMO the information about how many elements of AC belong to ABC / how many elements of BC belong to ABC is necessary
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by missrochelle » Fri Aug 27, 2010 7:06 am
can u use a venn diagram for this one? or is that too complicated? with these i am tryig to figure the most efficient way venn diagram vs. AuB formula. what is the formula for example?

set A = A - AUB - AUC ?
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by ankurmit » Fri Aug 27, 2010 8:22 am
Neerj.. can you please ppost solution of this quistion
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