A system that combines radar and infrared can be installed in cargo sh

A system that combines radar and infrared can be installed in cargo ships and passenger liners to provide a ship’s crew with a warning if another vessel is in the shipping lane directly ahead. The early warning allows a ship’s captain to attempt an abrupt course change to avert a possible collision. Even though cargo ships and passenger liners need a considerable distance to maneuver and that most warnings are false, such an early warning system undoubtedly better protects cargo and passengers. Which one of the following, if true, most strengthens the argument?

Option saying abrupt changes are safe and can be done without any harm will ensure the safety and hence strengthen the argument.
because this is the assumption here.

A. The system can detect not only the physical presence of a ship by radar but it can also detect a ship's heat signature by infrared.
Not relevant

B. A maritime safety commission report determined that over 82% of the system’s warnings were false.
It may be false but does it harm the cargos or passengers? It rather weakens if it harms.

C. Ship collisions in the major oceanic shipping lanes are extremely rare.
Not relevant

D. The risk of a cargo ship or passenger liner being involved in a collision is substantially greater at port than at sea.
Not relevant

E. Abrupt course changes do not involve risk to a ship’s cargo or passengers.
Yes this option explains it.

Im with you - E, but for other reasons.
A - Not relevant to the argument
B - Not relevant to the argument
C - This would weaken rather than strengthen (though also irrelevant)
D - This would weaken rather than strengthen
E - Correct choice (IMHO) as it eliminates possibility of weakness - conclusion is that the new system better PROTECTS the ship´s cargo and passengers, we could argue that it may protect the ship from collision but in doing so, passengers may get hurt, which would actually kill the argument. With this option we no longer can attack the argument

Asssumption: Such a security system would not pose any harm to the cargo while manoeuvring.....

The answer is E...

Abrupt course changes do not involve risk to a ship’s cargo or passengers

So the system would not pose any harm to the passengers or the Cargo and hence strengthens the assumption.

A system that combines radar and infrared can be installed in cargo ships and passenger liners to provide a ship’s crew with a warning if another vessel is in the shipping lane directly ahead. The early warning allows a ship’s captain to attempt an abrupt course change to avert a possible collision. Even though cargo ships and passenger liners need a considerable distance to maneuver and that most warnings are false, such an early warning system undoubtedly better protects cargo and passengers. Which one of the following, if true, most strengthens the argument?

A. The system can detect not only the physical presence of a ship by radar but it can also detect a ship's heat signature by infrared.

B. A maritime safety commission report determined that over 82% of the system’s warnings were false.

C. Ship collisions in the major oceanic shipping lanes are extremely rare.

D. The risk of a cargo ship or passenger liner being involved in a collision is substantially greater at port than at sea.

E. Abrupt course changes do not involve risk to a ship’s cargo or passengers.


Official Explanation
Type: Strengthen
Boil It Down: System warns captain -> Better protection
Missing Information: There are not any significant downsides to the system
Goal: Find the option that reinforces the notion that cargo and passengers will be better protected

Ⓐ This option just describes some of the details of HOW the technology works, but better knowing how it works in no way helps us know that it actually works, or will ultimately better protect cargo and passengers. By gaining a brief run-through of the systems involved, we are in no way better able to say that the system is more likely to achieve its goal—protection.

Ⓑ No effect. A high volume of false alarms wouldn’t help reinforce the positive outcome of the system, in fact, if anything, this option appears to even weaken the notion of how effective the system is if false alarms make up that big a fraction of the system’s warnings.

Ⓒ We’re not concerned with how rare or how common collisions are. Even if they’re rare, preventing them could be extremely valuable in protecting cargo, passengers, and ships. The notion of how rare such collisions are in no way reinforces the argument.

Ⓓ This option is utterly useless. It stresses the severity of locations outside of the scope of where we need it (avoiding collisions in sea lanes). This is what we call an Out Of Focus option. It just has no obvious impact on the argument concerning collision warning in sea lanes.

Ⓔ Yes! Although this option doesn’t DEFINITIVELY prove that the system will better protect cargo or passengers, it rules out a factor that could completely undercut the value of the system. Consider the alternative: what if the course changes did involve risk to a ship’s cargo or passengers? Then the system, especially if it had a significant number of false alarms, could, surprisingly, end up harming a ship’s cargo or passengers. By ruling out that risk, we reinforce the prediction that a ship’s cargo or passengers will be better protected.


Bigger GMAT Picture: Eliminating a likely alternative factor can reinforce the predicted outcome.

Hi vikal,

Thanks for weighing in, and for your speed in doing so! Option A merely describes the system's sensors, but that would only strengthen the argument if we assume that these features contributes to the goal of better protection of cargo and passengers (the goal isn't detection--the goal is protection). Does knowing what gizmos the system uses automatically help show that the system is any good at better protecting cargo and passengers? No.

This option would be like running through all of the specs on a car, but would that necessarily help prove an argument that the car is likely to win the race? Same flaw in A here.

Hi PUNEETSCHDV and jayanthjanardhan,

Thanks for chiming in on the thread! The problem with D is that how do we know the system is any good at all at port? With D, we'd have to assume that that it is and on top of that, according to the prompt the system scans in front of the ship. While at port, a forward-looking sensor might not be of much use at all.

This is how I came about getting E.

Abbreviated passage:
There is a system (radar + infrared) for ships that warns if another vessel is in the shipping lane.
The early warning is good to avoid collision with an abrupt course change. Warming not always true.
Argument = the system better at protecting cargo/passenger

Strengthen question

A. The system can detect not only the physical presence of a ship by radar but it can also detect a ship's heat signature by infrared.
repeating the given info in the passage - not relevant

B. A maritime safety commission report determined that over 82% of the system’s warnings were false.
repeating the given info in the passage - not relevant

C. Ship collisions in the major oceanic shipping lanes are extremely rare.
if true, defeats the purpose of having the system

D. The risk of a cargo ship or passenger liner being involved in a collision is substantially greater at port than at sea.
compares port vs sea - out of scope

E. Abrupt course changes do not involve risk to a ship’s cargo or passengers.
the passage indicates that abrupt course changes can save ships from colliding. if abrupt course changes does not cause additional problems, then early warning system indeed helps

Conclusion:Early warnings better protect the passengers and cargo

Between A and E

A slightly supports the the argument by telling the importance of IR,but this tells how system works.

Negating E will weaken the conclusion.If abrupt course changes involve the the risk to passengers and cargo,then early warnings that make sailor to make abrupt course change will not better protect passengers and cargo.So,E is best option.

You got it. +1

A is a strengthen answer. No way around that. It provides more than one way to detect ships which could potentially improve the chance that it helps to protect cargo and passengers. If radar fails, for example, heat signature is also available. The problem with A is that the connection is tenuous and doesn't really improve the situation because we never doubted the accuracy of the system to begin with (if radar was mentioned in the stimulus and there was concern about it, then this would be a really good answer). Additionally, E is better connected to the conclusion, so it technically "most strengthens" the argument.

I wouldn't rely too extensively on having to make such close determinations, as the GMAT seems to be slightly better about making sure that the trap answers clearly aren't as helpful as the credited response, so don't fret about this question.

Also, I wanted to mention one other thing (and this is really why I commented). While negating the answer does weaken the conclusion, that is not necessary for a correct strengthen response. You shouldn't use the negation technique to prove a strengthen answer, as many strengthen answers aren't required assumptions - only use negations for assumptions and inferences. In fact, E is actually an assumption (and this question might be better if it was changed into an assumption, because it would better remove A from consideration).

To chose between A and E
in infrared => since detection of temp is done at relatively short distance by infrared temp sensing equipment so the warning will be given at short range and in the stem its mentioned that for avoiding collision a little time is required to take action as the helm will take time to alter the ship to new course and the other ship will be cleared by a good range, so if detection by infrared is at small distance=> collision chances are there. REJECTED
However in E , Abrupt alterations do not cause risk to passengers or cargo=> so when ever the alarm is there of other vessel approaching-> the duty officer on the ship alters the course and even if the alteration is wide => abrupt alteration , causes no risk but saves collision.


A) tech is good but no where mentioned it can reduce collision.
E) course alteration => no effect on cgo and pax => officer is free to alter as much as he like in order to avoid of risk of collision. THEREFORE E is winner.

P.S. => I am a Navigating Officer, doing these alterations on daily basis.

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