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vishugogo: Master | Next Rank: 500 Posts; Posts: 131; Joined: Tue Aug 30, 2011 4:50 amFollowed by: 6 members; Location: India; Thanked: 28 times

by vishugogo » Tue Aug 13, 2013 11:02 am

At a certain company , 40% of women are over 50 years old and 50% of the men are over 50 years old. What percentage of the company are men?

1) 42% of all employees are over 50 years old.

2) There are 500 employees at the company.

OA A

I solved using Alligation

Using Statement 1:

Women 40----42-----50 Men.

Women/Men = 8/2 = 4/1

Here Men percentage is 20%

Sufficient

My question -- How is 20% the answer to question

Statement 2: Not sufficient

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Source: Beat The GMAT — Problem Solving | Tue Aug 13, 2013 11:02 am

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by [email protected] » Tue Aug 13, 2013 1:21 pm

Hi vishugogo,

Using the info from the prompt combined with the info from Fact 1, we have this...

F = Total number of Females
M = Total number of Males

40% of all women are over 50
50% of all men are over 50
42% of all employees are over 50

.4F + .5M = .42(F + M)

Now combine terms and simplify:
.4F + .5M = .42F + .42M
.08M = .02F
8M = 2F

M/F = 2/8
M/F = 1/4

So, for every 1 man, there are 4 women...
So, there is 1 man for every 5 total people

1/5 = 20%

GMAT assassins aren't born, they're made,
Rich

Contact Rich at [email protected]

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ganeshrkamath: Master | Next Rank: 500 Posts; Posts: 283; Joined: Sun Jun 23, 2013 11:56 pmFollowed by: 26 members; Location: Bangalore, India; Thanked: 97 times; GMAT Score:750

by ganeshrkamath » Tue Aug 13, 2013 9:50 pm

vishugogo wrote:At a certain company , 40% of women are over 50 years old and 50% of the men are over 50 years old. What percentage of the company are men?

1) 42% of all employees are over 50 years old.

2) There are 500 employees at the company.

OA A

I solved using Alligation

Using Statement 1:

Women 40----42-----50 Men.

Women/Men = 8/2 = 4/1

Here Men percentage is 20%

Sufficient

My question -- How is 20% the answer to question

Statement 2: Not sufficient

Statement 1 : 0.42 (M + W) = 0.4W + 0.5M
0.02W = 0.08M
W = 4M
So percentage of employees who are men = M / (M+W) * 100 % = M/(5M) * 100% = 20%
Sufficient.

Statement 2 : 500 employees in the company.
Since there's no information about the number of men or women, this information is useless.
Hence, not sufficient.

Choose A

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GMAT Score: 750 V40 Q51 AWA 5 IR 8
https://www.beatthegmat.com/first-attemp ... tml#688494

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