Each of people voted once in an election, X got 483 from male voters, Y got 433 from female voters. How many votes did X get?
1) X got votes from 50% of male voters
2) Y got votes from 60% of female voters
OAB
Each of people voted once in an election, X
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We can use the Double Matrix Method here to help us arrange our information. The Double Matrix can be used for most questions featuring a population in which each member has two characteristics associated with it.canbtg wrote:Each of people voted once in an election, X got 483 from male voters, Y got 433 from female voters. How many votes did X get?
1) X got votes from 50% of male voters
2) Y got votes from 60% of female voters
Here, we have a population of voters, and the two characteristics are:
- male or female
- voted for X or voted for Y
So, we can set up out diagram as follows:
X got 483 from male voters, Y got 433 from female voters.
We can add that information as follows:
Target question: How many votes did X get?
Notice that the two blue boxes represent the males and females who voted for X.
So, our goal here is to find the sum of these two boxes.
Statement 1: X got votes from 50% of male voters
The two highlighted boxes represent the male voters. If 50% of them voted for X, then the other 50% voted for Y.
So, 483 of the males also voted for Y...
We can now see that we don't have enough information to find the sum of the values in the 2 blue boxes
As such, statement 1 is NOT SUFFICIENT
Statement 2: Y got votes from 60% of female voters
The two highlighted boxes represent the female voters.
Let's let F = the total number of female voters.
If 60% of the females voted for Y, then we can write 0.6F = 433
If we wanted to, we COULD solve this equation for F, at which point we COULD ALSO determine the number of females who voted for X.
Since we COULD determine the number of females who voted for X, then we COULD ALSO find the total number of people who voted for X
Since we could easily answer the target question with certainty, statement 2 is SUFFICIENT
Answer: B
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Then try these additional practice questions that can be solved using the Double Matrix Method:
- https://www.beatthegmat.com/mba/2011/05/ ... question-1
- https://www.beatthegmat.com/mba/2011/05/ ... question-2
- https://www.beatthegmat.com/mba/2011/05/ ... question-3
- https://www.beatthegmat.com/ds-quest-t187706.html
- https://www.beatthegmat.com/overlapping- ... 83320.html
- https://www.beatthegmat.com/finance-majo ... 67425.html
- https://www.beatthegmat.com/ds-french-ja ... 22297.html
- https://www.beatthegmat.com/sets-t269449.html#692540
- https://www.beatthegmat.com/in-costume-f ... tml#692116
Cheers,
Brent
Last edited by Brent@GMATPrepNow on Wed May 16, 2018 4:25 am, edited 2 times in total.
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Hmmm, if it's an official GMATPrep question then either I'm missing something totally basic, or the question was not transcribed correctly. Here's why:canbtg wrote:thanks Brent . The question is from GMATPREP QP .
Let's let F = the total number of female voters.
It is given that 433 of the females voted for Y
Statement 2 say that 60% of the females voted for Y.
This mean that we can write 0.6F = 433
So, F = 433/0.6 = 721 2/3
This doesn't make any sense. We can't have 721 2/3 females.
Cheers,
Brent
I get your point . This is from some online resource tagged with GMATPREP Question (totally , misleading) . SO , I am sorry for creating a confusion .Brent@GMATPrepNow wrote:Hmmm, if it's an official GMATPrep question then either I'm missing something totally basic, or the question was not transcribed correctly. Here's why:canbtg wrote:thanks Brent . The question is from GMATPREP QP .
Let's let F = the total number of female voters.
It is given that 433 of the females voted for Y
Statement 2 say that 60% of the females voted for Y.
This mean that we can write 0.6F = 433
So, F = 433/0.6 = 721 2/3
This doesn't make any sense. We can't have 721 2/3 females.
Cheers,
Brent
I could Actually trace the original GMAT question :
Each vote in a certain election went to one of the two candidates, X or Y. Candidate X received 624 of the votes cast by men , and candidate Y received 483 of the votes cast by women , how many votes did X receive?
A. Candidate X got 50% of the votes cast by men.
B. Candidate Y got 60% of the votes cast by women.
OA
B
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Does the new statements mean
1. Candidate X got 50% of the votes cast by men. = x got 50% of votes from men
2. Candidate Y got 60% of the votes cast by women. = y got 60 % of votes from women
1- In this case X got 624 votes from men so total votes X got = 624 * 2 = 1248 - SUFFICIENT
2. In this case Y got 483 votes from women so 60% of Y = 483 gives Y = 805 - NOT SUFFICIENT.
Answer should be A
1. Candidate X got 50% of the votes cast by men. = x got 50% of votes from men
2. Candidate Y got 60% of the votes cast by women. = y got 60 % of votes from women
1- In this case X got 624 votes from men so total votes X got = 624 * 2 = 1248 - SUFFICIENT
2. In this case Y got 483 votes from women so 60% of Y = 483 gives Y = 805 - NOT SUFFICIENT.
Answer should be A