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All geologists must pass a written test and a field test to become lic 15 Oct 2019, 02:40
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35% (medium)

Question Stats:

71% (01:40) correct 29% (01:43) wrong based on 282 sessions

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All geologists must pass a written test and a field test to become licensed. If 70% of geologists pass the written test and 90% of geologists pass the fieldtest, what percent pass both tests?

(1) 10% did not pass either test.

(2) 20% passed only the field test.
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D
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All geologists must pass a written test and a field test to become lic 15 Oct 2019, 03:39
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Bunuel
All geologists must pass a written test and a field test to become licensed. If 70% of geologists pass the written test and 90% of geologists pass the fieldtest, what percent pass both tests?

(1) 10% did not pass either test.

(2) 20% passed only the field test.
Show more


Assume that there are 100 geologists applying for a license. As per the question stem,
70 pass the written test and 90 pass the field test. We don't know how many people
pass both the tests.

1. 10% did not pass either test -> Neither = 10

Total = P(W) + P(F) - Both + Neither -> 100 = 70 + 90 - Both + 10 -> Both = 70 (Sufficient)

2. 20% passed only the field test -> P(Only F) = 20

We know that P(F) = P(Only F) + Both -> Both = P(F) - P(Only F) = 90 - 20 = 70 (Sufficient - Option D)
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All geologists must pass a written test and a field test to become lic 15 Oct 2019, 03:57
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Bunuel
All geologists must pass a written test and a field test to become licensed. If 70% of geologists pass the written test and 90% of geologists pass the fieldtest, what percent pass both tests?

Let the pass percent of both = X


(1) 10% did not pass either test.

--> Sufficient

(2) 20% passed only the field test.
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--> Sufficient

IMO Option D
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All geologists must pass a written test and a field test to become lic 15 Oct 2019, 04:20
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Bunuel
All geologists must pass a written test and a field test to become licensed. If 70% of geologists pass the written test and 90% of geologists pass the field test, what percent pass both tests?

(1) 10% did not pass either test.

(2) 20% passed only the field test.
Show more

Let, the number of geologists= 100
So, the number geologists who pass the written test=70, and
The number of geologists who pass field test=90

Let, the number of geologist that pass both the tests= x
So, the number geologists who only pass the written test=70-x, and
The number of geologists who only pass field test=90-x

Let, number of geologists who do not pass either test=n

Thus, total number of geologists=70-x+x+90-x+n=100
So, if we can find either n or x, we can find the remaining details.

(1) n=10
Thus, sufficient.

(2) This statement says that 90-x=20
=> x=70
Thus, sufficient.

Therefore, the correct answer is option D.
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All geologists must pass a written test and a field test to become lic 19 Jan 2021, 01:45
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Bunuel
All geologists must pass a written test and a field test to become licensed. If 70% of geologists pass the written test and 90% of geologists pass the fieldtest, what percent pass both tests?

(1) 10% did not pass either test.

(2) 20% passed only the field test.
Show more

Veritas Prep Official Explanation



For Data Sufficiency Venn Diagram problems, treat them as problem-solving exercises, but make sure that you don’t carry information or forget about neither. Label what you know from the question in the Venn Diagram and then treat each statement separately:



Statement (1) is clearly sufficient, as you could just use the formula to see that it will give you both: 100 = 70 + 90 – B + 10.

Statement (2) is also sufficient, because when you plug in “Only P” = 20 in the diagram above, you can see that “Both” must be 70 to sum up to 90 for the whole circle.

Answer choice D is correct.

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All geologists must pass a written test and a field test to become lic 17 Jul 2025, 12:34
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