Does Country X have more citizens than Country Y?

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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.

OA C

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by Jay@ManhattanReview » Sun Sep 09, 2018 10:23 pm

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BTGmoderatorDC 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.

OA C

Source: Veritas Prep
Let's take each statement one by one.

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

We can have both the results: 1. Country X has more citizens than Country Y. and 2. Country Y has more citizens than Country X.

Case 1: Say, the number of citizens from Country X = 100 and the number of citizens from Country Y = 70, then 60 citizens from Country X can also be citizens of Country Y. The answer is Yes, Country X (100) has more citizens than Country Y (70).

Case 2: Say, the number of citizens from Country X = 100 and the number of citizens from Country Y = 1000, then 60 citizens from Country X can also be citizens of Country Y. The answer is No, Country X (100) does NOT have more citizens than Country Y (1000).

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

=> 70% of Country Y's citizens are also citizens of Country X.

As with Statement 1, the same with Statement 2.

Case 1: Say, the number of citizens from Country Y = 100 and the number of citizens from Country X = 70, then 70 citizens from Country Y can also be citizens of Country X. The answer is No, Country X (70) does have more citizens than Country Y (100).

Case 2: Say, the number of citizens from Country Y = 100 and the number of citizens from Country X = 1000, then 70 citizens from Country Y can also be citizens of Country X. The answer is Yes, Country X (1000) has more citizens than Country Y (100).

Insufficient.

(1) and (2) together

Say, the number of citizens from Country X = X and the number of citizens from Country Y = Y

=> 60% of X = 70% of Y

=> 6X = 7Y

=> X > Y. Sufficicient.

The correct answer: C

Hope this helps!

-Jay
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