a data from gmat forum

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a data from gmat forum

by diebeatsthegmat » Fri Sep 23, 2011 2:18 pm
Are at least 20% of the people in City H who are at least 30 years old bilingual?

1. In City H, 25 percent of the bilingual population is at least 30 years old.
2. In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual.

can you explain in details for me? i also think A works

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by cans » Fri Sep 23, 2011 7:55 pm
20% people: 30+ + bilingual????

A) 25% of b is 30+. but we don't know how many are b. if b is only 5%, then only 1.25% is 30+ + b
and if b=80%, 20% is 30+ +b. insufficient

B) we don't know how many men, how many women, and how many atleast 30 years old
Insufficient

A&B) insufficient.
IMO E
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by navami » Mon Sep 26, 2011 1:06 am
I will go for E too
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by Anurag@Gurome » Mon Sep 26, 2011 5:27 am
diebeatsthegmat wrote:Are at least 20% of the people in City H who are at least 30 years old bilingual?

1. In City H, 25 percent of the bilingual population is at least 30 years old.
2. In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual.

can you explain in details for me? i also think A works
From statement 1, nothing can be said regarding bilingual; NOT sufficient.
Statement 2: If women = 1000 and men = 100, then total bilingual = 180 + 170 = 350 or we can say 35% > 20%
If women = 100 and men = 1000, then total bilingual = 170 + 18 = 188 or we can say 18.8% < 20%
No unique answer; NOT sufficient.

Combining (1) and (2) also, we can say nothing definite.

The correct answer is E.
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by badpoem » Mon Sep 26, 2011 9:30 am
Anurag@Gurome wrote:
diebeatsthegmat wrote:Are at least 20% of the people in City H who are at least 30 years old bilingual?

1. In City H, 25 percent of the bilingual population is at least 30 years old.
2. In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual.

can you explain in details for me? i also think A works
From statement 1, nothing can be said regarding bilingual; NOT sufficient.
Statement 2: If women = 1000 and men = 100, then total bilingual = 180 + 170 = 350 or we can say 35% > 20% ---> Correction. total bilingual = 180 + 17 (17% of 100) = 197. Percentage = 197/1100 * 100 ~~17.9%

If women = 100 and men = 1000, then total bilingual = 170 + 18 = 188 or we can say 18.8% < 20%
No unique answer; NOT sufficient.

Combining (1) and (2) also, we can say nothing definite.

The correct answer is E.

I would beg to differ with Anurag here. The answer should be B. Hell, I had gone with E too, in one CAT from Knewton but the explanation pointed me out to where I had gone wrong.

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by rahulvsd » Mon Sep 26, 2011 7:33 pm
Hi,
I think this question is similar to this GMAT prep DS. See link https://www.manhattangmat.com/forums/are ... t5216.html

I think B will be sufficient to give a definite no to the question. please correct me if am wrong.

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by gmatboost » Mon Sep 26, 2011 7:56 pm
Are at least 20% of the people in City H who are at least 30 years old bilingual?
2. In City H, of the population at least 30 years old, 18 percent of the women and 17 percent of the men are bilingual.
If 17% of men in a certain group are bilingual and 18% of women in a certain group are bilingual, then, ASSUMING THE GROUP HAS ONLY WOMEN AND MEN, between 17% and 18% of people in that group are bilingual. So, statement 2 is sufficient (the definitive answer is "NO").

Of course, there could be children, etc. So the question should be more precise.
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