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vd
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How many of n pairs of twins are girls (1) 17 pair of the 19 Jun 2008, 05:01
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How many of n pairs of twins are girls

(1) 17 pair of the twins are boy-boy twins and 23 pair of the twins are boy-girl twins
(2) 1/6 of the twin pairs are not girl-girl twins

i am explaining the solution. can u please tell me if this is correct

Statement 1 does not give us the total no of pairs so this statement is insufficient, as using the given information only we cannot find out what is the total number of girl-girl twins
Statements 2 as such does not give us more information and hence is insufficient
Together both statements put together we cannot still know as to what is the total number of pairs (and statement 1 only provides us some specific details and not the details of the total population of the twins)

So E should be the answer



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How many of n pairs of twins are girls (1) 17 pair of the 19 Jun 2008, 05:06
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I choose C.

200 pairs of girl-girl twins
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alpha_plus_gamma
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How many of n pairs of twins are girls (1) 17 pair of the 19 Jun 2008, 05:10
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vdhawan1
How many of n pairs of twins are girls

(1) 17 pair of the twins are boy-boy twins and 23 pair of the twins are boy-girl twins
(2) 1/6 of the twin pairs are not girl-girl twins

i am explaining the solution. can u please tell me if this is correct

Statement 1 does not give us the total no of pairs so this statement is insufficient, as using the given information only we cannot find out what is the total number of girl-girl twins
Statements 2 as such does not give us more information and hence is insufficient
Together both statements put together we cannot still know as to what is the total number of pairs (and statement 1 only provides us some specific details and not the details of the total population of the twins)

So E should be the answer
Show more

IMHO,

C should be the answer
there are 3 possibilities, boy-boy twins, boy-girl twins , and girl-girl twins

combining 1 & 2, 17+23 =40 pairs are "non girl-girl pairs of twin" which is 1/6 of twin pairs. thus suff.
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anisen943
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How many of n pairs of twins are girls (1) 17 pair of the 19 Jun 2008, 05:44
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Agree C should be the answer.

Total number of twin pairs = 240
Out of which non-girl twin pairs = 40
Therefore, girl-girl pairs = 200
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How many of n pairs of twins are girls (1) 17 pair of the 19 Jun 2008, 23:40
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alpha_plus_gamma
vdhawan1
How many of n pairs of twins are girls

(1) 17 pair of the twins are boy-boy twins and 23 pair of the twins are boy-girl twins
(2) 1/6 of the twin pairs are not girl-girl twins

i am explaining the solution. can u please tell me if this is correct

Statement 1 does not give us the total no of pairs so this statement is insufficient, as using the given information only we cannot find out what is the total number of girl-girl twins
Statements 2 as such does not give us more information and hence is insufficient
Together both statements put together we cannot still know as to what is the total number of pairs (and statement 1 only provides us some specific details and not the details of the total population of the twins)

So E should be the answer

IMHO,

C should be the answer
there are 3 possibilities, boy-boy twins, boy-girl twins , and girl-girl twins

combining 1 & 2, 17+23 =40 pairs are "non girl-girl pairs of twin" which is 1/6 of twin pairs. thus suff.
Show more


Thanks for pointing this out. The OA indeed is C only

guess i must have been sleeping when i was solving this. why cud i not see that there are 40 no girl-girl twins (per statement 1) which represents 1/6 of the total population (per statement 2).

Therefore C should follow

Neways thanks for the help
appreciate it
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How many of n pairs of twins are girls (1) 17 pair of the 20 Jun 2008, 09:27
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vdhawan1
How many of n pairs of twins are girls

(1) 17 pair of the twins are boy-boy twins and 23 pair of the twins are boy-girl twins
(2) 1/6 of the twin pairs are not girl-girl twins

i am explaining the solution. can u please tell me if this is correct

Statement 1 does not give us the total no of pairs so this statement is insufficient, as using the given information only we cannot find out what is the total number of girl-girl twins
Statements 2 as such does not give us more information and hence is insufficient
Together both statements put together we cannot still know as to what is the total number of pairs (and statement 1 only provides us some specific details and not the details of the total population of the twins)

So E should be the answer
Show more

I got C.

There are three types of twin pairs : boy - boy, boy - girl and girl - girl. We are looking for the number of girl - girl pairs.
Statement 1 provides us with information about the two groups but not the group we're after not sufficient.
Statement 2 provides us with information about the girl girl twin pair but is not sufficent to calculate the total number. Not sufficient. Putting the two statements together (1 & 2), We already know the total of two of the groups and statement two tells us that this makes up 1/6 of the total. We can therefore calculate the girl girl pair with this information.



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This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
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Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!