Data Sufficiency Problem

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jba05d: Junior | Next Rank: 30 Posts; Posts: 18; Joined: Tue May 19, 2009 6:12 pm; Thanked: 3 times

by jba05d » Thu Jun 04, 2009 4:46 pm

I ran across this very simple Data Sufficiency Problem but got the problem wrong when I tried to solve it. I think the problem is just worded poorly, but maybe someone can point out what I am missing. The question is as follows:

Of 4800 voters who voted for Resolution K, 1800 were Democrat and 3000 were Republican. What was the total number of female voters who voted for Resolution K?

a. ¾ of Democrats & 2/3 of Republicans voted for Resolution K
b. 1/3 of Democrats who voted for Resolution K and ½ of Republicans who voted for Resolution K were female

The correct answer is C. However, it would seem that Statement 2 by itself is sufficient. The question asks for the total number of female voters that voted for Resolution K. The stem States that 4800 voters voted, and that 1800 of the voters were Dems and 3000 Reps. Therefore, if 1/3 Dems who voted voted for Res. K are female and 1/2 of Rep. who voted are female, then we sshould be able to derive the answer from the statement. In my opinion, Statement 1 seems to be simply stating that 3/4 of total dems 2/3 of total repub voted not necesarrily the dems and repubs mentioned in the question stem. Am I missing something or is this question just worded very poorly.

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Source: Beat The GMAT — Data Sufficiency | Thu Jun 04, 2009 4:46 pm

Osirus@VeritasPrep: GMAT Instructor; Posts: 1578; Joined: Thu May 28, 2009 8:02 amFollowed by: 34 members; Thanked: 128 times; GMAT Score:760

Re: Data Sufficiency Problem

by Osirus@VeritasPrep » Thu Jun 04, 2009 5:33 pm

jba05d wrote:I ran across this very simple Data Sufficiency Problem but got the problem wrong when I tried to solve it. I think the problem is just worded poorly, but maybe someone can point out what I am missing. The question is as follows:

Of 4800 voters who voted for Resolution K, 1800 were Democrat and 3000 were Republican. What was the total number of female voters who voted for Resolution K?

a. ¾ of Democrats & 2/3 of Republicans voted for Resolution K
b. 1/3 of Democrats who voted for Resolution K and ½ of Republicans who voted for Resolution K were female

The correct answer is C. However, it would seem that Statement 2 by itself is sufficient. The question asks for the total number of female voters that voted for Resolution K. The stem States that 4800 voters voted, and that 1800 of the voters were Dems and 3000 Reps. Therefore, if 1/3 Dems who voted voted for Res. K are female and 1/2 of Rep. who voted are female, then we sshould be able to derive the answer from the statement. In my opinion, Statement 1 seems to be simply stating that 3/4 of total dems 2/3 of total repub voted not necesarrily the dems and repubs mentioned in the question stem. Am I missing something or is this question just worded very poorly.

I'm assuming this isn't from an OG because that question is worded incorrectly. If they want C to be the answer then in the first sentence of the premise they meant to say "of 4800 of voters who voted ON Resolution K", not "for"

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jba05d: Junior | Next Rank: 30 Posts; Posts: 18; Joined: Tue May 19, 2009 6:12 pm; Thanked: 3 times

by jba05d » Thu Jun 04, 2009 5:38 pm

That's what I thought also. And it is not from the OG.

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Sm1520: Junior | Next Rank: 30 Posts; Posts: 15; Joined: Fri Feb 05, 2010 4:50 am

by Sm1520 » Mon Oct 11, 2010 4:06 am

This ques is from GMAT Prep 1. The correct 1 is as follows:

Of 4800 voters who voted for or against Resolution K, 1800 were Democrat and 3000 were Republican. What was the total number of female voters who voted for Resolution K?
a. Â¾ of the Democrats & 2/3 of the Republicans voted for Resolution K
b. 1/3 of the Democrats who voted for Resolution K and Â½ of Republicans who voted for Resolution K were female

OA is C

Makes sense now. .

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oberlove: Newbie | Next Rank: 10 Posts; Posts: 3; Joined: Fri Jan 08, 2010 8:36 am

by oberlove » Sun Oct 17, 2010 9:28 am

Sm1520 wrote:This ques is from GMAT Prep 1. The correct 1 is as follows:

Of 4800 voters who voted for or against Resolution K, 1800 were Democrat and 3000 were Republican. What was the total number of female voters who voted for Resolution K?
a. Â¾ of the Democrats & 2/3 of the Republicans voted for Resolution K
b. 1/3 of the Democrats who voted for Resolution K and Â½ of Republicans who voted for Resolution K were female

OA is C

Makes sense now. .

************************
Would the best way to set up this equation be by setting up a matrix or by using Venn Diagrams?

I'm still not clear on the best way to find a solution. I need a visual crutch to help me out here.

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Geva@EconomistGMAT: GMAT Instructor; Posts: 905; Joined: Sun Sep 12, 2010 1:38 amFollowed by: 123 members; Thanked: 378 times; GMAT Score:760

by Geva@EconomistGMAT » Mon Oct 18, 2010 3:08 am

An interesting question. My first thought was that it definitely needs a grid and not venn, as the distinctions are democrat/republican and male/female - two separate distinctions, with all four possible interactions. The problem is that there's the additional dimension of voted FOR or AGAINST - I realized that only when I constructed the table below, and tried to see what's the next step.

Bottom line: organizing all the information here "by the book" would actually require linking two separate tables: democrat/republican, male female FOR, and
democrat/republican, male female AGAINST.

However, there really is no need to go this far: Since both the question stem and the statements only focus on the "for" side, I ignored the "against" side in my solution (in effect focusing only on the "FOR" table). But you have to keep in mind that Without this added dimension, stat. (2) would be indeed sufficient on its own: if the 4800, 18000 and 3000 were the voters FOR (not for or against), then the number of females would be a straightforward 1/3*1800+1/2*3000. All Stat. (1) does is make that transition from "for or against" to "only for".

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