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# M00-02

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Math Expert
Joined: 02 Sep 2009
Posts: 56244

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16 Sep 2014, 00:14
00:00

Difficulty:

15% (low)

Question Stats:

88% (01:43) correct 12% (02:23) wrong based on 41 sessions

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Among the 750 employees of Massco Corporation 60% are women, and 90% are non-smokers. If 80% of the smokers are men, what is the number of female non-smokers?

A. 58
B. 240
C. 435
D. 450
E. 780

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Posts: 56244

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16 Sep 2014, 00:14
Official Solution:

Among the 750 employees of Massco Corporation 60% are women, and 90% are non-smokers. If 80% of the smokers are men, what is the number of female non-smokers?

A. 58
B. 240
C. 435
D. 450
E. 780

* S N T M 8 32 40 W 2 58 60 T 10 90 100
Where M means men, W - women, S - smokers, N - nonsmokers, and T - total (100%). So, the percent we need is 58%.

Therefore, 0.58*750=435. On the GMAT, you don't need exact calculations, just take 0.6*750, which is 0.3*1,500 = a bit less than 450.

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07 Feb 2016, 16:55
I am confused to see 435 as the answer.

As i understand, among 750 employees 60% are women, that will be 450 women; which leaves 300 men.and if 90% of women are non-smokers that will be 90% of 450 which is 405. 450-405 = 45 women non-somokers; and 45 is 20% of 225, which means 225-45=180 men smokers account for 80% of the smokers

Men= 300, smokers 180, non-smokers 120
Women =450, smokers 45, non-smokers 405
Employees=750(300+450), Smokers 225(45+180), Non-smokers 525 (120+405)

Now smokers+ non-smokers equal to 525+225=750
Men + women =300+450 =750
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Joined: 02 Aug 2009
Posts: 7764

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07 Feb 2016, 18:41
1
aqeelnaqvi10 wrote:
I am confused to see 435 as the answer.

As i understand, among 750 employees 60% are women, that will be 450 women; which leaves 300 men.and if 90% of women are non-smokers that will be 90% of 450 which is 405. 450-405 = 45 women non-somokers; and 45 is 20% of 225, which means 225-45=180 men smokers account for 80% of the smokers

Men= 300, smokers 180, non-smokers 120
Women =450, smokers 45, non-smokers 405
Employees=750(300+450), Smokers 225(45+180), Non-smokers 525 (120+405)

Now smokers+ non-smokers equal to 525+225=750
Men + women =300+450 =750

Hi,
you are wrongly taking 90% of women to be non smokrs..
overall 90% are non smokers, which means 10% are smokers..
or .1*750=75 are smokers..

now 80% of the smokers are men..
.8*75=60..
so female smokers=75-60=15..

female nonsmokers=450-15=435..
HOpe it helps u
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23 Apr 2018, 04:58
Bunuel wrote:
Official Solution:

Among the 750 employees of Massco Corporation 60% are women, and 90% are non-smokers. If 80% of the smokers are men, what is the number of female non-smokers?

A. 58
B. 240
C. 435
D. 450
E. 780

* S N T M 8 32 40 W 2 58 60 T 10 90 100
Where M means men, W - women, S - smokers, N - nonsmokers, and T - total (100%). So, the percent we need is 58%.

Therefore, 0.58*750=435. On the GMAT, you don't need exact calculations, just take 0.6*750, which is 0.3*1,500 = a bit less than 450.

I solved this question using the double set matrix. It took me about 1m45 secs.
I am unable to get the explanation provided here. Can someone help?
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Joined: 04 Sep 2016
Posts: 1360
Location: India
WE: Engineering (Other)

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10 Jul 2018, 17:16
Bunuel chetan2u pushpitkc pikolo2510 Abhishek009 niks18

I tried to use double matrix method (black and blue : given; red: calculated; highlighted: final ans )
but the approach is too prone to make calculation errors. Is there any option to simplify the same?
>> !!!

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Joined: 25 Feb 2013
Posts: 1197
Location: India
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11 Jul 2018, 09:18
1
Bunuel chetan2u pushpitkc pikolo2510 Abhishek009 niks18

I tried to use double matrix method (black and blue : given; red: calculated; highlighted: final ans )
but the approach is too prone to make calculation errors. Is there any option to simplify the same?

I think matrix method is one of the easiest and quickest for these type of questions. Alternatively you can also use tree-structure method but it will have same level of calculation as the matrix method

Other way would be to simply treat it as a word problem and solve as per the given statements- step by step.
Re: M00-02   [#permalink] 11 Jul 2018, 09:18
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# M00-02

Moderators: chetan2u, Bunuel