Birthday party

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Birthday party

by pepeprepa » Wed Aug 27, 2008 9:15 am
Recently Mary gave a birthday party for her daughter at which she served both chocolate and strawberry ice cream. There were 8 boys who had chocolate ice cream, and 9 girls who had strawberry. Everybody there had some ice cream, but nobody tried both. What is the mawimum possible number of girls who had some chocolate ice cream?
1) Exactly thirty children attended the party
2) Fewer than half the children had strawberry ice cream

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by parallel_chase » Wed Aug 27, 2008 9:50 am
I would go for C.

Statement I

30 boys+girls

We dont know how many are boys and how many are girls.

Insufficient.

Statement II

We dont know the total number of boys and girls.


Combining I & II

No. of children who had strawberry can be 9 girls and 5 boys = 14
remaining 16 out of which 8 boys rest are girls who had chocolate.

Therefore Sufficient.

Hence C.

I was confused with the question initially, but the key word is "maximum possible"
Last edited by parallel_chase on Wed Aug 27, 2008 10:06 am, edited 1 time in total.

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by Suyog » Wed Aug 27, 2008 9:55 am
Wots the OA?
IMO A.

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Re: Birthday party

by sudhir3127 » Wed Aug 27, 2008 10:02 am
pepeprepa wrote:Recently Mary gave a birthday party for her daughter at which she served both chocolate and strawberry ice cream. There were 8 boys who had chocolate ice cream, and 9 girls who had strawberry. Everybody there had some ice cream, but nobody tried both. What is the mawimum possible number of girls who had some chocolate ice cream?
1) Exactly thirty children attended the party
2) Fewer than half the children had strawberry ice cream
i think its C

question stem says 8 boys had choc ice creams and 9 girls had strawberry.

statement 1. total 30.

insufficient

statement 2. fewer than half children had strawberry ice creams
so it can be 14,13,.........

in sufficient

combining 1 and 2

we know 30 children and max 14 children had strawberry

out of these 14 .. we know 9 are girls from question stem

thus the rest 5 are boys...

thus the total number of boys who had some ice creams are 8+ 5 = 13

there fore girls who had some ice creams ( max) = 30 - 13 = 17

thus C

do let us know the OA

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by canuckclint » Wed Aug 27, 2008 10:17 am
I say the anwer is C. Here is why.

Draw a table:

- C S
B 8 y
G x 9

From 1. 8+x+y+9 = 30
From 2. y + 9 < (8 + x + y + 9)/2
Simplifying 1, we get x+y = 13.
Substitute x+y with 13 in 2:
y + 9 < (8 + 13 + 9) / 2
Solving this out we get y < 6

From 1. all the numbers in table have to add up to 30.
Check for youself
y = 5. Then x = 8
...
y= 0 Then x = 13

Max is 13. C
Btw, the max can't be 17 because then 8+9+17 will be 34 over.

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MGMAT Test review questions

by pepeprepa » Wed Aug 27, 2008 10:35 am
I am not totally clear on this question, hope this explanation is sufficient. I have the feeling that these 2 sentences apart give 2 different scenarios and I chose C.

Here is the explanation (forget the "-" I wanted to made a table)

----B------G
C--8----- a---b
S--c------9---d
----------------30

We want to maximize a so let's take c=0 --> 9+0=d --> d=9 --> b+9=30 --> b=21 --> 21-8=a --> a=13

Indeed, the fact that half the children had strawberry ice cream is not important when we have 1) because whatever happens we will try to have the smallest c, so 0.

OA:A


What do you think about the same question except a change for the 2) statement: More than half the children had strawberry ice cream

(Sorry for my previous "aaa" post, it was a post manipulation error...)
Last edited by pepeprepa on Wed Aug 27, 2008 10:47 am, edited 4 times in total.

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by Suyog » Wed Aug 27, 2008 10:38 am
its A right?

or 3 times a i.e. C :lol:

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Re: MGMAT Test review questions

by sudhir3127 » Wed Aug 27, 2008 10:41 am
pepeprepa wrote:aaa
is it A?

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by Suyog » Wed Aug 27, 2008 10:47 am
it can't be 17 for sure..

boys and choc 8, girls and str 9

if total is 30 and nobody had both then 8+9= 17
30 - 17 = 13

It shud be A cause q asks what is maximum possible count.
and (I) itself gives us 13
Last edited by Suyog on Thu Aug 28, 2008 3:36 am, edited 1 time in total.

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by mehravikas » Wed Aug 27, 2008 8:01 pm
Answer should be 'C', because we cannot find the ratio of boys to girls in the remaining 13 children.

There could be 11 boys + 2 girls or the other way round.

However, statement 2 tells us that total number of strawberry was fewer than half.

Half of strawberry = 30/2 = 15

To find the maximum possible count, pick the number of strawberries as 14 (Picking this number because "Everybody there had some ice cream, but nobody tried both"). Therefore, 5 boys must have had strawberry.

Hope its clear.
Suyog wrote:it can't be 17 for sure..

boys and choc 8, girls and str 9

if total is 30 and nobody had both then 8+9= 17
30 - 17 = 13

It shud be A cause q asks what is maximum possible count.
but (I) itself gives us 13

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by pepeprepa » Thu Aug 28, 2008 1:49 am
@mehravikas
"Half of strawberry = 30/2 = 15"
You are true
"To find the maximum possible count, pick the number of strawberries as 14 "
You are wrong, that's why 2) does not bring anything to statement 1).
Because 2) tells you "Fewer than half the children had strawberry ice cream", does not mean they are 14 who had strawberry ice cream, it could be 0. 0 is impossible given the question but 9 is the minimum.
If you want to maximize the number of girls who take chocolate, you will not take 14 who had strawberry ice cream but you will take 9 otherwise you do not maximize.

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Re: Birthday party

by sb117 » Fri Aug 29, 2008 10:12 am
pepeprepa wrote:Recently Mary gave a birthday party for her daughter at which she served both chocolate and strawberry ice cream. There were 8 boys who had chocolate ice cream, and 9 girls who had strawberry. Everybody there had some ice cream, but nobody tried both. What is the mawimum possible number of girls who had some chocolate ice cream?
1) Exactly thirty children attended the party
2) Fewer than half the children had strawberry ice cream
The answer is A as we have to calc the maximum no. of girls taking strawb ice cream. so rest of 13 can be girls.
ratio of boys is irrelevant and not required

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by pranavc » Fri Aug 29, 2008 11:46 am
I am going with A. What is the OA?

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OA is A

by skvignesh » Sun May 17, 2009 7:25 am
Official Answer is A, but I am not sure if this is a good GMAT question.

I read somewhere (reliable) that in any DS question the actual solution will fit in both (A) and (B) in the real GMAT, it will never be so that the answer in (A) can be different from the answer in (B) so I think this is a wrong question in the first place.

Knowing that the source is Manhattan, its quite hard to digest, want any opinions on this.