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Does Country X have more citizens than Country Y?

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Does Country X have more citizens than Country Y? [#permalink]

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New post 23 Jan 2015, 07:45
1
3
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A
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C
D
E

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68% (01:03) correct 32% (01:07) wrong based on 173 sessions

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Does Country X have more citizens than Country Y?

(1) 60% of Country X's citizens are also citizens of Country Y.

(2) 30% of Country Y's citizens are not citizens of Country X.

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Re: Does Country X have more citizens than Country Y? [#permalink]

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New post 23 Jan 2015, 07:59
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Bunuel wrote:
Does Country X have more citizens than Country Y?

(1) 60% of Country X's citizens are also citizens of Country Y.

(2) 30% of Country Y's citizens are not citizens of Country X.

Kudos for a correct solution.


1) gives us the overlap of citizens between A and B. We have no way of figuring out the value of each indipendent group

not sufficient.

2) gives us Y's citizens. Not sufficient.

1+2) we can figure out B's citizens and thus estimate whether A>B. Sufficient.

Answer C.
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Re: Does Country X have more citizens than Country Y? [#permalink]

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New post 23 Jan 2015, 10:11
3
Draw two circle for X and Y.
The common part is 0.6X and 0.7X
0.6X = 0.7Y. X is higher than Y.

Although we don't need to answer Yes or No, this way does not taking too much time.
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Re: Does Country X have more citizens than Country Y? [#permalink]

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New post 26 Jan 2015, 04:49
Bunuel wrote:
Does Country X have more citizens than Country Y?

(1) 60% of Country X's citizens are also citizens of Country Y.

(2) 30% of Country Y's citizens are not citizens of Country X.

Kudos for a correct solution.


VERITAS PREP OFFICIAL SOLUTION:

In this Organizing Information / Venn Diagram problem you should see relatively quickly that neither statement alone is sufficient. For statement 1, for example, those 60% of Country X's citizens could be "all six" of Country Y's citizens (making X larger than Y with 10 citizens to 6) or could be 6 of a trillion citizens of Country Y (making Y exponentially larger).

So this problem comes down to C vs. E, and that should signal that it's time to do some work. Given the Venn Diagram structure of the problem, we know that we have an overlap of "both", and that that overlap represents:

60% of Country X's citizens

70% of Country Y's citizens (if 30% are not in the overlap, then 70% are)

So we know that .6X = .7Y, in which case we can solve that X/Y = 7/6, meaning that X definitely has a larger population than Y. Answer choice C is correct.
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Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


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Re: Does Country X have more citizens than Country Y? [#permalink]

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New post 17 Apr 2018, 21:08
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Re: Does Country X have more citizens than Country Y?   [#permalink] 17 Apr 2018, 21:08
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