Give it a whirl... -- In accordance with new legislation,

Question

Give it a whirl...
--
In accordance with new legislation, AirMax requires its pilots to record gauge readings at several set intervals during every flight. AirMax Craft 123 crashed due to engine failure, and the records kept by this craft's pilot on the plane's second-to-last flight, three days before the plane crashed, show a pattern of gauge readings consistent with the pattern that results when an engine is beginning to be dangerously corroded by rust. However, the plane's engine was recovered after the crash, and the amount of rust present in the engine was comparable to the amount present on engines of planes that successfully land at their destinations. This level of rust damage is much lower than the level of rust damage present on recovered engines of planes that crashed due to rust damage more than one day after gauge readings indicated that the engine was beginning to be dangerously corroded by rust.

Which of the following is most strongly supported by the statements given?

(A) The pattern of gauge readings recorded on the second to last flight of AirMax Craft 123 was caused by engine damage that was not due to rust.
(B) The crash of AirMax Craft 123 was not the result of any kind of engine damage.
(C) The pattern of gauge readings recorded on the second to last flight of AirMax Craft 123 was not a result of plane's engine being dangerously corroded by rust.
(D) The pattern of gauge readings observed by the pilot on the last flight of AirMax Craft 123 must have been different from the pattern recorded by the pilot on AirMax Craft 123's second to last flight.
(E) It is unusual for a plane whose pattern of gauge readings indicates that the engine is dangerously corroded by rust to successfully land if the plane takes off more than a day after this pattern of gauge readings is recorded.

nverma · Answer

IMHO C.

praveenism · Answer

IMO C....
The stem clearly indicates that a serious damage by rust later appears in indication network.
Since the indications stated early, and the rust is much less compared to other "Rust damage accidental planes", it can be easily infered that rust is not the cause of accident. I suppose....the reasoning is lucid.
Right....Eagerly waiting for answer.....

achan · Answer

IMO C

JoshKnewton · Answer

I'm going to post the explanation around 3pm EDT. For now keep the answers coming!

anish319 · Answer

IMO D

JoshKnewton · Answer

An answer strongly supported by the statements must directly follow from the information given, just as a conclusion would.

We are presented with a few facts:

Pilots record gauge readings at several intervals on each AirMax flight.
The gauge readings on a flight of AirMax Craft 123 were consistent with the pattern of gauge readings observed when an engine is beginning to be dangerously corroded by rust. 
Three days after these readings, the plane crashed.
The engine recovered from the craft and displayed a certain amount of rust. This level of rust was not enough, in and of itself, to cause a plane to crash; we know this because it is the same level found in planes that landed successfully.
The level of rust damage on the engine of AirMax Craft 123 is less than the level of rust damage on planes that crash due to rust damage more than a day after gauge readings indicated that the engine was beginning to be dangerously corroded by rust.
Choice C directly follows from the statements. Remember, there are four separate types of plane at play in this argument: planes that show gauge readings that imply the beginnings of serious rust damage (from 2), planes that land successfully (from 4), planes that crashed more than one day after having bad gauge readings (from 5), and AirMax Craft 123 itself. The gauge readings of each of these planes is named in the abstract; let's actually plug in values just to keep track of all the complexities.

There are also two types of reading- engine readings, which are official, and patterns of gauge readings, which are predictive.

Let's say that some planes that land successfully have engines with a level of 48 rust units (whatever those are). That means that AirMax Craft 123's engine must have a comparable level- say, 50 rust units- this comes from point (4). AirMax Craft 123 is also said to have had a pattern of gauge readings that matches that of planes that are beginning to be dangerously corroded by rust. Let's call this a "Code Red" warning. AirMax Craft 123 had a "Code Red" warning, and so do the planes in (2). Thus, a plane with a "Code Red" warning can have an engine with a rust level of 50 three days later.

Now, the fourth entity- the really confusing one: planes that crash from rust damage more than one day after having bad readings. We know that the level of rust damage in the engines of those planes is much higher than in the others (from point 5), so let's call it 80 rust units. This implies that if a plane has a "Code Red", and then crashes after one day or more, a group which COULD include AirMax Craft 123, has a rust level of 80. We know that AirMax Craft 123 did have a "Code Red" and that it did crash; but its actual engine had only 50 rust units. Thus, it is not a member of the group of planes (in 5) that crashed due to rust damage. Choice C is correct.

Choice A is out of the scope of this argument; all that the argument states about a pattern of gauge readings is that the one observed is consistent with one that results when an engine begins to display signs of rust damage. There's no sure indication as to whether the plane's engine was actually damaged at all by anything.

Choice B, again, is out of the scope of the argument; the argument does not actually give the cause of the plane's crash. We only know that the engine's rust level was lower than rust levels observed when a sign indicates that the engine is dangerously corroded.

Choice D does not follow from the statements, which do not even address what the pattern is like on the day that a plane actually crashes.

Choice E makes a claim that is unsupported; the argument only addresses a group of planes that do fly more than a day after a sign indicates that the engine is dangerously corroded by rust. There is nothing stated about how likely it is for planes displaying these signs to crash before a day passes.

Choice C is correct.

cano · Answer

Hey, nice question.
Unfortunately I was late. Keep it a little longer next time so those of us who live in the other side of the globe have a chance of solving the exercise without the OA.
Please post questions more often!!

dwivedys · Answer

I was confused between C and E. Very tough question. Thanks Josh..pls post more such questions if possible.

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