Sure thing, vasuca10!


Highway Official: When resurfacing our concrete bridges, we should use electrically conductive concrete (ECC) rather than standard concrete. In the winter, ECC can be heated by passing an electric current through it, thereby preventing ice buildup. The cost of the electricity needed is substantially lower than the cost of the de-icing salt we currently use.

Taxpayer: But construction costs for ECC are much higher than for standard concrete, so your proposal is probably not justifiable on economic grounds.

Which of the following, if true, could best be used to support the highway official’s proposal in the face of taxpayer’s objection?

So, we're looking to address why the choice to use ECC rather than standard concrete would be justifiable on economic grounds, despite the fact that construction costs are higher than for standard concrete.

(A) The use of de-icing salt causes corrosion of the reinforcing steel in concrete bridge decks and damage to the concrete itself, thereby considerably shortening the useful life of concrete bridges. <- If de-icing salt lessens the useful life of concrete structures, this provides an excellent reason why ECC might make more economic sense, despite the higher construction costs. If ECC lasts longer and costs less to maintain temperature control - it could make economic sense despite the higher construction costs! We have our answer!

(B) Severe icing conditions can cause power outages and slow down the work of emergency crews trying to get power restored. <- Pretty irrelevant to us here, as both perspectives in our argument are addressing options for building/maintaining safe roadways, not whether or not we need de-icing options at all!

(C) In weather conditions conducive to icing, ice generally forms on the concrete surfaces of bridges well before it forms on parts of the roadway that go over solid ground. <- Again, this doesn't address the potential net difference in cost between regular concrete + de-icing vs. ECC.

(D) Aside from its potential use for de-icing bridges, ECC might also be an effective means of keeping other concrete structures such as parking garages and airport runways ice free. <- Effectiveness isn't what we're addressing in this argument. The taxpayer is claiming that construction costs (regardless of whether this concrete structure is built for planes, trains, or automobiles!) make ECC a less economically viable option. We need something that tells us ECC is in fact economically viable/wise, despite these construction costs, and (D) fails to address this.

(E) If ECC were to be used for a bridge surface, the electric current would be turned on only at times at which ice was likely to form. <- We only use the current when needed, we only de-ice when needed... again, this doesn't bring a new piece of evidence into the mix that addresses why ECC is economically viable despite its higher construction costs.

So, we want to be sure we're addressing the argument and conclusion presented to us. (That seems to be where you got caught up here.) Here, we aren't just trying to address why ECC is "good" or "effective," we want something that specifically counters the taxpayer's argument and addresses why it is economically justified as compared to the use of traditional concrete. Only (A) accomplishes this goal.
_________________

my take is A :The use of de-icing salt causes corrosion of the reinforcing steel in concrete bridge decks and damage to the concrete itself, thereby considerably shortening the useful life of concrete bridges.

We are looking for an answer that supports the fact that ECC in the long-period will be cheaper than normal concrete

A. The use of de-icing salt causes corrosion of the reinforcing steel in concrete bridge decks and damage to the concrete itself, thereby considerably shortening the useful life of concrete bridges.
CORRECT: corrosion = short life = more money spent on repairs and maintenance
B. Severe icing conditions can cause power outages and slow down the work of emergency crews trying to get power restored.
This is not related to costs.
C. In weather conditions conducive to icing, ice generally forms on the concrete surfaces of bridges well before it forms on parts of the roadway that go over solid ground.
Again , out of scope because doen't adess the point.
D. Aside from its potential use for de-icing bridges, ECC might also be an effective means of keeping other concrete structures such as parking garages and airport runways ice free.
Out of scope
E. If ECC were to be used for a bridge surface, the electric current would be turned on only at times at which ice was likely to form.
This doesn't show that ECC will save more money than normal concrete.It only says that the electric current would be turned on only at times at which ice was likely to form, so that ECC will be used "wisely"...

Highway Official: When resurfacing our concrete bridges, we should use electrically conductive concrete (ECC) rather than standard concrete. In the winter, ECC can be heated by passing an electric current through it, thereby preventing ice buildup. The cost of the electricity needed is substantially lower than the cost of the de-icing salt we currently use.

Taxpayer: But construction costs for ECC are much higher than for standard concrete, so your proposal is probably not justifiable on economic grounds.

How can v support the highway official’s proposal in the face of taxpayer’s objection?

A answers that:

The use of de-icing salt causes corrosion of the reinforcing steel in concrete bridge decks and damage to the concrete itself, thereby considerably shortening the useful life of concrete bridges.
Traditional approach -> shortens life of bridge considerably -> increases the cost.
Now, HO proposal: ECC -> removing ice from road using electricity -> cost of the electricity needed is substantially lower than the cost of the de-icing salt

options B,C,D and E are out of scope or irrelevant options
option A clearly exposes the fault in reasoning that by using de-icing salt , corrosion of steel structures occurs thereby shortening their life so correct
correct answer - A

DavidTutorexamPAL VeritasKarishma generis

Could you explain what is issue with (E)?


HO: Use ECC than SC (std concrete)
(y) because it is more effective than using de-icing salt since electricity is cheaper


T: No, we should not use ECC since its construction costs are higher than SC


So I have to strengthen HO's claim (use ECC) and weaken T 's claim

This option is adding more weight to HO's premise (use electricity than salt) by mentioning we use electricity ONLY WHEN ice is likely to form.
_________________

Let me try to help you with this part

In strengthen/weaken questions, we need to bring in outside information in order to support/ weaken the argument.
If we consider option E, its already implied from the argument , so that is one way where you can reject option E
Hope this helps!

VeritasPrepHailey mam Please guide for this question... I was stuck in two answer choices A and D and eventually marked incorrect answer choice D

Conclusion that needs to be strengthened is to use ECC instead of standard concrete as 1) It prevents ice buildup during winters 2) Cost of Electricity needed is less than cost of deicing salt

What I thought was Option D is strengthening our conclusion by advocating why ECC is effective for usage

Kindly explain process of elimination for all Options mam so that I can know where is the mistake in my thought process

Wow mam the way in which you explain my doubts is simply commendable

Kudos to you mam

I am able to arrive at my mistake now, I interpreted conclusion partially correct and focused only on effectiveness of ECC as compared to standard concrete structure and did not focused on cost part

Excellent explanation mam

Highway Official: When resurfacing our concrete bridges, we should use electrically conductive concrete (ECC) rather than standard concrete. In the winter, ECC can be heated by passing an electric current through it, thereby preventing ice buildup. The cost of the electricity needed is substantially lower than the cost of the de-icing salt we currently use.

Taxpayer: But construction costs for ECC are much higher than for standard concrete, so your proposal is probably not justifiable on economic grounds.

Which of the following, if true, could best be used to support the highway official’s proposal in the face of taxpayer’s objection?

Answer: A

(A) The use of de-icing salt causes corrosion of the reinforcing steel in concrete bridge decks and damage to the concrete itself, thereby considerably shortening the useful life of concrete bridges. -- CORRECT, this clearly says that the so-called benefits of using de-icing salt on EEC inadvertently causes damage to the concrete and offsets the savings done by lowered cost of de-icing. This adds up to construction cost as well, hence weakening the highway official's proposal.

(B) Severe icing conditions can cause power outages and slow down the work of emergency crews trying to get power restored. -- "Severe icing conditions" are special cases and typical trap options

(C) In weather conditions conducive to icing, ice generally forms on the concrete surfaces of bridges well before it forms on parts of the roadway that go over solid ground. -- The process of icing formation is not important to conclusion

(D) Aside from its potential use for de-icing bridges, ECC might also be an effective means of keeping other concrete structures such as parking garages and airport runways ice free. -- We are not worries about other usages of EEC in this passage

(E) If ECC were to be used for a bridge surface, the electric current would be turned on only at times at which ice was likely to form. -- The technicalities don't matter.

Proposal: “we should use electrically conductive concrete (ECC) rather than standard concrete.” How can we support this, given the taxpayer said it costs too much? What if in the long run it saves a bunch of money, outweighing the construction costs?

Which of the following, if true, could best be used to support the highway official’s proposal in the face of taxpayer’s objection?

A. The use of de-icing salt causes corrosion of the reinforcing steel in concrete bridge decks and damage to the concrete itself, thereby considerably shortening the useful life of concrete bridges.
This hits the argument from the other side. The de-icing process isn’t good. In the long run, it seems like it could potentially cost more. So why not invest up front, so costs won’t be incurred (potentially more costs) down the road?

B. Severe icing conditions can cause power outages and slow down the work of emergency crews trying to get power restored.
This neither supports nor weakens the proposal. Also seems like both salt and electricity can do this.

C. In weather conditions conducive to icing, ice generally forms on the concrete surfaces of bridges well before it forms on parts of the roadway that go over solid ground.
Where it forms is irrelevant. We want to know how this ECC stuff can be better than standard concrete, despite high construction costs.

D. Aside from its potential use for de-icing bridges, ECC might also be an effective means of keeping other concrete structures such as parking garages and airport runways ice free.
The scope of the argument is the concrete bridges and how the construction costs are high (thus not justified). We don’t care about the parking garages and airports, at least the way this answer is framed.

E. If ECC were to be used for a bridge surface, the electric current would be turned on only at times at which ice was likely to form.
Doesn’t address the objections piece. This is after the fact. The objection focuses on the initial cost (i.e., the construction cost).

Let’s look at the highway official’s argument-

Premises

In the winter, ECC can be heated by passing an electric current through it, thereby preventing ice buildup.
The cost of the electricity needed is substantially lower than the cost of the de-icing salt we currently use.

Conclusion/opinion

When resurfacing our concrete bridges, we should use electrically conductive concrete (ECC) rather than standard concrete.

Now, let’s look at the taxpayer’s argument

Premises

construction costs for ECC are much higher than for standard concrete,

Conclusion/opinion
so your proposal is probably not justifiable on economic grounds.


We need to find an option that would support the highway official’s proposal in the face of taxpayer’s objection.

(A) The use of de-icing salt causes corrosion of the reinforcing steel in concrete bridge decks and damage to the concrete itself, thereby considerably shortening the useful life of concrete bridges.


De-icing salt is what we currently use. Option A says that the use of de-icing salt causes corrosion of the reinforcing steel in concrete bridge decks and damage to the concrete itself, thereby considerably shortening the useful life of concrete bridges. This strengthens the highway official’s proposal that we should use electrically conductive concrete (ECC) rather than standard concrete. ECC can be heated by passing an electric current through it, thereby preventing ice buildup. Therefore using ECC is justifiable on economic grounds Correct.

(B) Severe icing conditions can cause power outages and slow down the work of emergency crews trying to get power restored.

Irrelevant. The conclusion is related to the use of ECC. Eliminate

(C) In weather conditions conducive to icing, ice generally forms on the concrete surfaces of bridges well before it forms on parts of the roadway that go over solid ground.

Same as B. Eliminate.

(D) Aside from its potential use for de-icing bridges, ECC might also be an effective means of keeping other concrete structures such as parking garages and airport runways ice free.

When resurfacing our concrete bridges, we should use electrically conductive concrete (ECC) rather than standard concrete.
parking garages and airport runways ice free- Out of scope. Eliminate

(E) If ECC were to be used for a bridge surface, the electric current would be turned on only at times at which ice was likely to form.

Does not matter. Eliminate.

Vishnupriya
GMAT Verbal SME
_________________

Hi! This question is tagged 'Weaken', shouldn't it be tagged 'Strengthen' instead? Thanks.

______________________
Edited the tag. Thank you!
_________________

Sure thing! In fact I should be the one thanking you and this forum. The question filtering system has made it incredibly convenient to work on my weaker topics.

choosing best option tosupport official claim
option A

Concrete Bridges


Step 1: Identify the Question

The phrases support the official’s proposal and if true in the question stem indicate that this is a Strengthen the Argument question.


Step 2: Deconstruct the Argument

Official: ECC uses elec to melt ice;

Std needs salt, which is > $ than elec

© resurface bridges with ECC and not Std.

Taxpayer: But ECC is >> $ than Std

Note: Std is used as an abbreviation for standard concrete.



Step 3: Pause and State the Goal

In Strengthen questions, the correct answer should make the conclusion more likely. In this case, you are asked to support the official’s proposal in the face of the taxpayer’s objection. The objection is that since ECC is more expensive than standard concrete, the proposal to use ECC is not economically justified. Look for an answer that shows how using ECC might still be more cost-effective for resurfacing the bridges.



Step 4: Work from Wrong to Right

(A) CORRECT. If the use of deicing salt on standard concrete bridges leads to shorter lifespans for those bridges, then more money will be spent on rebuilding bridges. The use of deicing salt, necessitated by using standard concrete, has a hidden cost, thus strengthening the official’s position that ECC is the better resurfacing option for economic reasons.

(B) This answer choice gives reasons for why it is wise to prevent ice buildup, but ice buildup can be prevented on bridges with either type of concrete (with electrical current on ECC and with salt on standard concrete). Further, it does not present any information regarding economic cost. Therefore this choice doesn’t address the official’s proposal or the taxpayer’s rebuttal.

(C) This answer choice distinguishes between concrete bridge surfaces and non-bridge surfaces, but it does not distinguish between ECC and standard concrete on bridges. Therefore this choice doesn’t address the official’s proposal or the taxpayer’s rebuttal.

(D) The argument is concerned with resurfacing bridges, only. The versatility of ECC and how it might be effective on other surfaces does not influence whether it is the more cost-effective option when it comes to resurfacing bridges.

(E) This answer choice effectively restates the premise that using electricity for ECC is cheaper than using deicing salt, since electricity will not be used at times when it is unnecessary to do so. It does not offer new information to properly address the taxpayer’s objection, which relates to the high cost of the ECC itself.

Hi Avi - is this the way to eliminate E


(E) strengthens the blue premise specifically.

We already know per the blue premise, cost of electricity is lower to the cost of de-icing salt.

(E) just gives us one more reason to believe the cost of providing electricity is LOWER than the cost of de-icing salt.

(E) doesnt address the twin challenge that