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irishiraj87
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generis interesting question :? :-) considering the fact this is kinda of a cr question :-) ...hmm if father is dead , i mean he really died in car accident, and son survived... there should be some close relative or simply a mother (in this particular case) in surgeons in place because surgeon says I can’t operate — that boy is my son. so if one of them died, and if surgeon says "I can’t operate — that boy is my son" so that makes me think that surgeon was mother.
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adkikani
KarishmaB generis nightblade354 gmatexam439 GMATNinja

Hi Experts, please help to understand why (D) is wrong on basis of below formula:

Average speed = total distance / total time

Since this is a paradox question, let us first understand what is the paradox:

Quote:
The faster a car is traveling, the less time the driver has to avoid a potential accident, and if a car does crash, higher speeds increase the risk of a fatality. Between 1995 and 2000, average highway speeds increased significantly in the United States, yet, over that time, there was a drop in the number ofcar-crash fatalities per highway mile driven by cars.

More speed of car -> Less time a driver has to avoid an accident.
So More speed -> More chance of fatal accidents.

1995 - 2000 : AVERAGE SPEED on highway increased.
So what is expected?
More no of fatal accidents.
But ACTUALLY,
drop in fraction: no of car-crash fatalities / Distance

Option D clearly says: average mileage has increased. Mileage means no of kms travelled per unit consumption of fuel.
If the denominator increases, fraction decreases and hence paradox is resolved.
I considered (B) out of scope since it does not express any variable in my fraction.
Let me know flaws in my understanding.

Yes, it is a tricky thing and certainly hard to explain. Though I have tried to do it here: https://www.gmatclub.com/forum/veritas-prep-resource-links-no-longer-available-399979.html#/2016/0 ... reasoning/

Also, mileage here has nothing to do with consumption of fuel. It is just the average miles driven per car on highways.
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generis
A father and son are in a horrible car crash that kills the dad. The son is rushed to the hospital; just as he’s about to go under the knife, the surgeon says, “I can’t operate — that boy is my son!” Explain.

The surgeon = Stepfather or stepmother would explain that paradox.
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generis
A father and son are in a horrible car crash that kills the dad. The son is rushed to the hospital; just as he’s about to go under the knife, the surgeon says, “I can’t operate — that boy is my son!” Explain.

The surgeon = Stepfather or stepmother would explain that paradox.


hazelnut nice guess :)

Ok here ia a question for you hazelnut :lol:

Gays are becoming increasingly more but they don’t reproduce themselves.

Which helps to resolve paradox ? :lol:
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dave13
Gays are becoming increasingly more but they don’t reproduce themselves.

Which helps to resolve paradox ? :lol:

Gay couple could probably adopt a child.
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Okay based on explainations of VeritasKarishma ma'am and my own reasoning, simply we can say that the argument is dependent on:

#fatality / # of miles travelled

Agreed to it, but there are two equations to the problem

#fatality = k ( positive constant) * Speed

Based on second formula, it can be said for option D that the #fatality will increase making the rate = ( #fatality/ #miles travelled) a constant since both have increased and this might increase the gap in the paradox.

I believe this reasoning is sound.
In option B, we derive one more equation that weakens our second equation ( the relation between fatality and speed) and hence it helps reduce the gap of our paradox
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Reasoning What could explain:
why the number of fatalities per highway mile driven declined even as average highway speeds increased?

We are told that
"higher speeds mean a higher risk of fatalities, other things being equal".
Consequently, the increasing highway speeds between 1995 and 2000 should have led to more fatalities per highway mile driven.
Since the fatalities per mile driven actually decreased, some countervailing factor must have
- increased driving safety more than enough to compensate for the danger of the higher speeds.

Additional Information needed: Thus, find an answer option suggesting how a factor that increased driving safety became more common or effective between 1995 and 2000.

A More passengers per car would likely mean even more fatalities per highway mile driven,
since more people would die per car accident.

B Correct.
More seatbelts and airbags would have probably reduced the average number of fatalities per car accident,
resulting in fewer fatalities per mile driven
even if the higher speeds resulted in more car accidents.

C This cannot help explain the decrease in fatalities.
Driving at a higher speed probably increases the risk of a fatal car accident
regardless of whether the speed is legal or illegal.

D Fewer accidents per highway mile driven could explain
- why the average highway mileage per car increased?
(since some cars would have gone more miles before crashing),
but the converse is not correct: the increased average mileage could not explain
why there were fewer accidents per mile driven?

E Instead of explaining
why there was a decrease in the number of fatalities per highway mile driven?
this merely rules out the possibility that the explanation
was a lower density of cars on the highways!
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OFFICIAL EXPLANATION


Reasoning- What could explain why the number of fatalities per highway mile driven declined even as average highway speeds increased? We are told that higher speeds mean a higher risk of fatalities, other things being equal. Consequently, the increasing highway speeds between 1995 and 2000 should have led to more fatalities per highway mile driven. Since the fatalities per mile driven actually decreased, some countervailing factor must have increased driving safety more than enough to compensate for the danger of the higher speeds. Thus, find an answer option suggesting how a factor that increased driving safety became more common or effective between 1995 and 2000.

A. More passengers per car would likely mean even more fatalities per highway mile driven, since more people would die per car accident.
B. Correct. More seatbelts and airbags would have probably reduced the average number of fatalities per car accident, resulting in fewer fatalities per mile driven even if the higher speeds resulted in more car accidents.
C. This cannot help explain the decrease in fatalities. Driving at a higher speed probably increases the risk of a fatal car accident regardless of whether the speed is legal or illegal.
D. Fewer accidents per highway mile driven could explain why the average highway mileage per car increased (since some cars would have gone more miles before crashing), but the converse is not correct: the increased average mileage could not explain why there were fewer accidents per mile driven.
E Instead of explaining why there was a decrease in the number of fatalities per highway mile driven, this merely rules out the possibility that the explanation was a lower density of cars on the highways.

The correct answer is B.
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