The cause of the wreck of the ship Edmund in a severe storm

Question

The cause of the wreck of the ship Edmund Fitzgerald in a severe storm on Lake Superior is still unknown. When the sunken wreckage of the vessel was found, searchers discovered the hull in two pieces lying close together. The storm’s violent waves would have caused separate pieces floating even briefly on the surface to drift apart. Therefore the breakup of the hull can be ruled out as the cause of the sinking.

Which of the following is an assumption on which the argument depends?

A. Ships as large as the Edmund rarely sink except in the most violent weather.
B. Underwater currents at the time of the storm did not move the separated pieces of the hull together again.
C. Pieces of the hull would have sunk more quickly than the intact hull would have.
D. The waves of the storm were not violent enough to have caused the ship to break up the surface.
E. If the ship broke up before sinking, the pieces of the hull would not have remained on the surface for very long.

ID 00905

Kris01 · Accepted Answer

Hello mun23,

Hope I can help you with this one.

The argument states that the ship was found broken in two pieces. These two pieces were found right next to each other. However, the waves of a storm would have separated any two pieces floating for even a short while in the sea. Since the two pieces were not found far from each other, the ship's breakage might not be the cause for its sinking. The assumption here is that the waves could not have separated and then brought back the two pieces together so that they could be found right next to each other.

This point is clearly stated in option B.

However, let us analyze all the options one by one.

(A)Ships as large as Edmund Fitzgerald rarely sink except in the most violent weather. This is irrelevant. The suinken wreckage of the ship was found. We do not care of the probability of a large ship sinking since we already know that this particular ship sunk. We need to find the reason that caused the ship to sink.

(B)Underwater currents at the time of the storm did not move the separated pieces of the hull together again. This option is the right answer based on previous explanation.
 
(C)Pieces of the hull would have sunk more quickly than the intact hull would have. This is irrelevant. It gives us no information about the role of waves in sinking the ship or whether the ship broke before sinking.

(D)The waves of the storm not violent enough to have cause the ship to break up on the surface. The waves might not have been strong enough to cause the breakage of ship. However, there might have been some other cause(e.g. colliding with an iceberg) for the breakage of ship which could have lead to its sinking. We are not concerned about the cause of the breakage of the ship.

(E)If the ship broke up before sinking,the pieces of the hull would not have remained on the surface very long. The argument mentions that the pieces were found sunk. Hence, this point is irrelevant.

Please let me know if you need any further clarification.

GMATNinja · Answer

The passage concludes that "the breakup of the hull can be ruled out as the cause of the sinking" because "the storm’s violent waves would have caused separate pieces floating  even briefly  on the surface to drift apart."

From this evidence, we know that the pieces would have drifted apart if they were separated on the surface for  even a very short amount of time . If the hull came apart on the surface, the pieces would separate whether they were only  "briefly"  on the surface and then sank, or whether they were on the surface for  a longer amount  of time and then sank.

The two pieces of the hull were found close together, leading the author to conclude that the pieces did  not  separate on the surface for even a brief length of time, and thus "the breakup of the hull can be ruled out as the cause of the sinking."

Take another look at answer (E):
 
This answer choice specifies that the pieces of hull would be on the surface for a "not... very long" time. As stated above, if the ship broke up before sinking, the pieces of hull would have drifted apart  almost immediately.

But remember, the author concludes that breakup of the hull did NOT cause the ship to sink. So it really doesn't matter how long the pieces might have been on the surface if the hull broke up BEFORE sinking, because the entire conclusion is that the hull did NOT break up before sinking.

The argument doesn't depend on (E) to be valid, so choice (E) is out.

I hope this helps!

mbaiseasy · Answer

Premise 1: Vessel found with the hull in two pieces lying close together...
Premise 2: The storm's violent waves would cause pieces to drift apart if separated...

Gap/Assumption: Found connected --> Hull were connected before sinking

Conclusion: The breakup of the hull is ruled out as the cause of sinking

A. The issue is whether the sinking was caused by the breakup of the hull. OUT!
B. If underwater currents connected the hull, then breakup ocurred before sinking. This doesn't rule out the breakup of the hull. BINGO!
C. Sinking speed is not the issue. The issue is whether the breakup of the hull is a suspect. OUT!
D. Seems like the ship might have sunk before breaking up... The strength of the storm doesn't affect the issue of whether to rule out the breakup of the hull as a cause.

Answer: B

rajathpanta · Answer

We need to keep the conclusion in perspective and then look out for assumption- Conclusion- the breakup of the hulls did not cause the ship to sink Premise- 2 pieces found together. He adds telling storms would have taken the 2 pieces far away Assumption (prethinking) - maybe since the pieces are together it is not the reason for the ship sinking Ans choice- ? A. Ships as large as the Edmund rarely sink except in the most violent weather. Ok we want info that relates to the 2 pieces of hull. we can put this could be true category. B. Underwater currents at the time of the storm did not move the separated pieces of the hull together again. hmmm.. looks good. PARK C. Pieces of the hull would have sunk more quickly than the intact hull would have. :idea:

we are worried about ship sinking here D. The waves of the storm were not violent enough to have caused the ship to break up the surface. Could be true. again E. If the ship broke up before sinking, the pieces of the hull would not have remained on the surface for very long Irrelavent. Uses a few words from the arguement to confuse us The option B is a 'defender' type assumption which defends the assumption telling 'there is no other cause for the hull being together'

btg9788 · Answer

This is a very good question..took me almost 2 minutes

The cause of the wreck of the ship Edmund Fitzgerald in a severe storm on Lake Superior is still unknown. When the sunken wreckage of the vessel was found, searchers discovered the hull in two pieces lying close together. The storm’s violent waves would have caused separate pieces floating even briefly on the surface to drift apart. Therefore the breakup of the hull can be ruled out as the cause of the sinking.

IT IS BEING ARGUED THAT THOUGH THE TWO PIECES OF HULL HAVE BEEN FOUND CLOSE TOGETHER UNDER WATER, THE BOAT DID NOT SINK DUE TO BREAKAGE OF HULL ABOVE WATER.....BECAUSE IF IT HAD BROKEN ABOVE WATER THE PIECES WOULD HAVE DRIFTED FAR APART.......
THEREFORE THE HULL DID NOT BREAK ABOVE WATER ... BUT MUST HAVE BROKEN UNDERWATER..........AND IT CAN BE ASSUMED THAT IT IS NOT THAT THE HULL BROKE ABOVE WATER AND THEN THE UNDERWATER CURRENTS BROUGHT THE TWO PIECES TOGETHER UNDERWATER.......------RATHER THE HULL MUST HAVE BROKEN UNDERWATER AND THEREFORE SINKAGE OF SHIP MAY NOT BE BECAUSE OF BREAKAGE OF HULL ABOVE WATER......

Which of the following is an assumption on which the argument depends?

A. Ships as large as the Edmund rarely sink except in the most violent weather. IRRELEVANT
B. Underwater currents at the time of the storm did not move the separated pieces of the hull together again.......CORRECT
C. Pieces of the hull would have sunk more quickly than the intact hull would have.QUICKLY ---- IRRELEVANT
D. The waves of the storm were not violent enough to have caused the ship to break up the surface.NO MENTION OF THIS NATURE
E. If the ship broke up before sinking, the pieces of the hull would not have remained on the surface for very long.WHAT WOULD HAVE HAPPENED AFTER THE SHIP BROKE IS IRRELEVANT

semwal · Answer

The cause of the wreck of the ship Edmund Fitzgerald in a severe storm on Lake Superior is still unknown. When the sunken wreckage of the vessel was found, searchers discovered the hull in two pieces lying close together. The storm’s violent waves would have caused separate pieces floating even briefly on the surface to drift apart. Therefore the breakup of the hull can be ruled out as the cause of the sinking.

IT IS BEING ARGUED THAT THOUGH THE TWO PIECES OF HULL HAVE BEEN FOUND CLOSE TOGETHER UNDER WATER,  THE BOAT DID NOT SINK DUE TO BREAKAGE OF HULL ABOVE WATER.....BECAUSE IF IT HAD BROKEN ABOVE WATER THE PIECES WOULD HAVE DRIFTED FAR APART....... 
THEREFORE THE HULL DID NOT BREAK ABOVE WATER ... BUT MUST HAVE BROKEN UNDERWATER.......... AND IT CAN BE ASSUMED THAT IT IS NOT THAT THE HULL BROKE ABOVE WATER AND THEN THE UNDERWATER CURRENTS BROUGHT THE TWO PIECES TOGETHER UNDERWATER....... ------RATHER THE HULL MUST HAVE BROKEN UNDERWATER AND THEREFORE SINKAGE OF SHIP MAY NOT BE BECAUSE OF BREAKAGE OF HULL ABOVE WATER......

Which of the following is an assumption on which the argument depends?

A. Ships as large as the Edmund rarely sink except in the most violent weather.  IRRELEVANT 
B. Underwater currents at the time of the storm did not move the separated pieces of the hull together again.... ...  CORRECT   
C. Pieces of the hull would have sunk more quickly than the intact hull would have. QUICKLY ---- IRRELEVANT 
D. The waves of the storm were not violent enough to have caused the ship to break up the surface. NO MENTION OF THIS NATURE 
E. If the ship broke up before sinking, the pieces of the hull would not have remained on the surface for very long. WHAT WOULD HAVE HAPPENED AFTER THE SHIP BROKE IS IRRELEVANT

mallya12 · Answer

i understand ans B but doubt is with E. if the pieces of the hull did remain on the surface for very long, then it would be separated by the violent waves. Wouldnt this destroy the conclusion.

I am confused someone please explain clearly

energetics · Answer

Premise: 
1) 2 pieces of sunken hull found close together
2) violent storm waves would cause broken pieces to immediately separate 
 Conclusion: 
3) the ship did not sink due to the hull breaking

A. Ships as large as the Edmund rarely sink except in the most violent weather. 
-- irrelevant, other ships don't matter
  B. Underwater currents at the time of the storm did not move the separated pieces of the hull together again.  
-- if the hull pieces moved later, then the ship might have sunk due the hull breaking, the pieces initially separated and this effect was masked by the currents, this strengthens the conclusion
 C. Pieces of the hull would have sunk more quickly than the intact hull would have. 
-- irrelevant, rate of sinking doesn't matter
 D. The waves of the storm were not violent enough to have caused the ship to break up the surface. 
-- irrelevant, we don't know what caused it to sink to begin with, maybe it wasn't the waves but that the ship hit a rocky shoal
 E. If the ship broke up before sinking, the pieces of the hull would not have remained on the surface for very long. 
-- actually weakens the conclusion, since then the ship could break up on the surface and then the pieces would not separate but sink down together

dcummins · Answer

Note: The ship was found sunken.

The author argues that the cause of the ship sinking was not the breakup of the actual ship itself otherwise the pieces would not have been found sunken together as they were.

Possible defenders:
- eliminate alternate causes
- show that when the cause happens the effect happens

A - is besides the argument. The fact of the matter is the Ship sunk.
C - besides the fact in similar fashion. The fact of the matter is the duration of time it took for pieces to sink is besides the fact that the ship did not break up before sinking.
D - There could have been an alternate cause for the ship breaking up on the surface prior to its sinking, so this does isn't necessary for the argument to be true as the argument relates to the cause-effect relationship between breaking up and sinking. 
Besides, the golden rule here for gmat questions is that "When the author makes his conclusion he believes it to be airtight, that is, he has considered and denied any other possibility".

E - If you negate this:
If the ship broke up before sinking, the pieces of the hull  would have  remained on the surface for very long
This wouldn't make sense and it would actually then contradict the premise and conclusion because the author's conclusion is based on the fact that "The storm’s violent waves would have caused separate pieces floating even briefly on the surface to drift apart"

B -  Negate to see if it weakens the conclusion, because if it does weaken the conclusion then we can show that the authors conclusion could be arrived at via a different route. 
Negated statement: Underwater currents at the time of the storm MOVED the separated pieces of the hull together again. 
Now considering the premise that "The storm’s violent waves would have caused separate pieces floating even briefly on the surface to drift apart", the conclusion that " the breakup of the hull can be ruled out as the cause of the sinking" is weakened because the ship could have broken up on the surface, separated miles apart because of the violent waves, then be brought back together again underwater.

Statement B denies the possibility of this happening i.e. before we negated it " underwater currents DID NOT MOVE..." -->Therefore statement B is a defender assumption (or passive assumption).

Alternatively  consider what "must be true" to arrive at the author's conclusion.
If we think a statement only  could  be true then it isn't required by the author to make his argument.
For example, it "could be true that underwater currents at the time did not move the separated pieces together"... NO. This statement MUST BE true otherwise, by lowering the probability of this occurring, we weaken the conclusion of the author.

siddhantvarma · Answer

Went through all the posts but still couldn't understand exactly what the argument is and how the given information is tied to it. After some tinkering, breaking down the passage and pieces of information to understand how the argument comes together.

Premise : The cause of the wreck of the ship is unknown. There was a severe storm, but that probably didn't cause the wreck. If it would have, the cause wouldn't be unknown. Everything else here is background information.

Info : When the wreck was discovered (it was sunk at the time of discovery), the hull lay on the  bottom  (since the hull came from the wreck and wreck itself was at the bottom of the sea) in two pieces close together.

Reasoning : Because the storm’s waves were so violent, if the hull had broken up while still afloat, the pieces would have drifted far apart on the surface.

Conclusion/Argument : Therefore the breakup of the hull can be ruled out as the cause of the sinking.
Therefore, since the pieces were, in fact, close together, the ship must have sunk intact (i.e., the breakup of the hull did not cause the sinking).

Once you understand all of the above, the answer comes naturally. For the conclusion to hold, it must be true that once those two pieces sank, nothing brought them back together. 
Otherwise, even if they had drifted apart on the surface, some underwater force (such as a current) could have repositioned them nearby on the lake bottom.

The only answer choice that aligns with the above logic is (B). 
This question was all about understanding the argument well.

The cause of the wreck of the ship Edmund in a severe storm

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The cause of the wreck of the ship Edmund in a severe storm

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