Car Owner: My mechanic believes that my car's wheels must be

Question

Car Owner: My mechanic believes that my car's wheels must be out of alignment because the fact that the tires are under-inflated cannot by itself account for the steering problems I have been having for the past several months. But Because my gas mileage has been steady during the same time period, the alignment of my car's wheels must be normal.

Which one of the following is an assumption required by the car owner's argument?

(A) A drop in gas mileage occurs only if a car's wheels are out of alignment.

(B) Under-inflated tires can cause a car's mileage to drop.

(C) A car's mileage varies less under test conditions than it does on the open road.

(D) Misaligned wheels can sometimes cause a car's mileage to drop.

(E) Under-inflated tires and misaligned wheels cannot both cause steering problems.

mbagal1 · Answer

The choice is obviously between A and D. alignment and mileage. Now between the two:

A) A drop in gas mileage occurs only if a car's wheels are out of alignment. 

(D) Misaligned wheels can sometimes cause a car's mileage to drop. 

Car owner says: But Because my gas mileage has been steady during the same time period, the alignment of my car's wheels must be normal. 

Cannot be that gas mileage reduces only when wheels are out of alignment, D expresses it better

yogeshsheth · Answer

Intially thought of A and D here. But A is strong statement and D is a mild one but second thoughts say E.

Swagatalakshmi · Answer

E !

mbagal1 · Answer

Can you please explain why you think it is E? Is it because he ignores the under-inflation of tires being a possible cause?

what about gas mileage? why don't we have to account for that in the assumption?

Thanks

yogeshsheth · Answer

He agrees that under inflation of tires can cause steering problems but disagrees with wheel alignment which means he feels both under inflation and wheel alignment cannot cause steering problems. This is what I feel.

u2lover · Answer

A is way too strong because of ONLY -> OUT

D... can you tell me where does the argument talk about CAR's MILEAGE... doesn't it talk about GAS MILEAGE... those are 2 different things IMO -> D is OUT

I am with E

mbagal1 · Answer

Hmm, so mileage and gas mileage are two different things? What does mileage mean in this context? 
What if D had said gas mileage instead of just mileage?

Thanks

u2lover · Answer

car's mileage = how many miles a car run in total

car's gas mileage = how many miles a car can run per 1 gallon of gas

another thing... SOMETIMES??? what about OTHER TIMES??? so even if you do change to "gas mileage" in D, this SOMETIMES seems a bit suspicious

mm007 · Answer

OA is D.

OE is:

A says if my mileage drops, then I know for sure that my wheels aren't aligned. But does it say anything about what's true if there is no drop in gas mielage. No, it doesn't. Because we only care what's true if there is no drop in gas mileage (because that's the premise in the argument), we can eliminate A.

E does not talk anything about the drop in mileage, which is the crucial part of owner's argument.

For D: however, if you negate D, misaligned wheels never cause a car's mileage to drop. If it were true that misaligned wheels could never be the cause of a decrease in a mileage, then how could the owner cite steady mileage as the proof that the wheels were aligned. Negated version of D destroys the argument, and is, therefore, the answer.

mbagal1 · Answer

Thanks, I needed that shot in the arm, I have been feeling less confident about my verbal lately.

buckkitty · Answer

Went with D too, but do not feel confident in the quality of the answer based on U2lover's explanation.

E is wrong b/c the car owner does not disagree that underinflated tires can cause steering problems, she just says that misaligned wheels HAS to be one of the causes. I dont think there is enough evidence to say E would qualify as an assumption.

Andr359 · Answer

Car wheels out of alignment = NOT A

Tires under inflated = UI

Steering Problems = SP

Gas mileage steady = GMS

The stem basically says: (SP & UI) => NOT A. GMS => A.

B can be stated as: IU => NOT GMS, which looks more like a "special case of the stem". As we see above, the stem is (SP & UI) => NOT A. NOT A => NOT GMS, in other words, SP & UI => NOT GMS. Sometimes SP = True, and therefore the expression is reduced to B: IU => NOT GMS.

I think that D rather re-states the conclusion (as its contrapositive): NOT A => NOT GMS (GM fluctuates, either up or down). 

Comments/ideas welcome.

buzzgaurav · Answer

E looks tempting at first but D it should be for the same reason.

Car Owner: My mechanic believes that my car's wheels must be

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