Dear experts, could you please explain why "D" is better than "A".

Based on Pareto's principle (80/20 rule), which is a concept taught and accepted in business school and arguably in real business world, the 20% loss in toll revenue may not be significant, since the remaining 80% of users will still pay increased toll fees.

But if "A" is true, then the authority may not even get the chance to collect increased revenue from the 80% of current highway users.

So why is "D" better than "A"?

Your advise will be appreciated, thanks!

Hi

Application of the Pareto principle to option (D) is a huge leap of faith. For starters, Pareto principle only states that 80% of the outcomes (in this case, maybe the toll) comes from 20% of the events (here, the toll payers). If we are going so far as to assume the Pareto principle, it is also logical to assume that the ones shifting to the longer route would be the ones most affected by the toll raise ie; the 20% of commuters who pay the 80% of toll collections. This indicates a failure of the plan. Pareto principle, in this case, would strengthen the case made by Option (D).

The most simple explanation for option (D) is that loss of 20% of toll paying commuters would, in the minimum, break the plan to finance these improvements over the course of five years - it would surely take longer.

Option (A) is incorrect because we do not know what the results of such hearings would be. It is possible that the plan may be supported, or not. We cannot assume that the plan will be opposed since we do not have any such indication from the passage.

Hope this helps.
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Great explanation by CrackVerbalGMAT!

For more on this, check out the explanation of (D) in the second half of this post.
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Got a bit confused by the stem. Is this a strengthening question in weakening form?

Hi lakshya14,

We are being asked to weaken the authority’s plan.
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According to the Tristate Transportation Authority, making certain improvements to the main commuter rail line would increase ridership dramatically. The authority plans to finance these improvements over the course of five years by raising automobile tolls on the two high-way bridges along the route the rail line serves. Although the proposed improvements are indeed needed, the authority’s plan for securing the necessary funds should be rejected because it would unfairly force drivers to absorb the entire cost of something from which they receive no benefit.

Which of the following, if true, would cast the most doubt on the effectiveness of the authority’s plan to finance the proposed improvements by increasing bridge tolls?


(A) Before the authority increases tolls on any of the area bridges, it is required by law to hold public hearings at which objections to the proposed increase can be raised. X

This is purely explanatory…it goes about giving us details about the circumstances surrounding the toll increase. Irrelevant.

(B) Whenever bridge tolls are increased, the authority must pay a private contractor to adjust the automated toll-collecting machines. X

Again, like A, this choice gives us supplemental details that really aren’t impactful at all insofar as weakening the effectiveness of the proposed plan is concerned.

(C) Between the time a proposed toll increase is announced and the time the increase is actually put into effect, many commuters buy more tokens than usual to postpone the effects of the increase.

The main contender. This choice essentially says commuters will try to postpone the toll increase. However, postponement doesn’t necessarily mean the plan won’t work.

(D) When tolls were last increased on the two bridges in question, almost 20 percent of the regular commuter traffic switched to a slightly longer alternative route that has since been improved.

Correct. The key to this choice is “that has since been improved”. Typically, the past isn’t a particularly reliable indicator of what will happen in the future, but presumably the improvements in those longer routes means commuters have a plan B. If, in the past, people were OK enough to take those routes, then now that they are improved, it’s not hard to imagine resorting to those routes again.

(E) The chairman of the authority is a member of the Tristate Automobile Club that has registered strong opposition to the proposed toll increase. X

Who cares what his/her opinion is.
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VeritasKarishma Hi there !
The plan is to get the money from people who travel on the highway within the 5 years
To cast doubt on the effectiveness, We can either cash doubt on : 1) Time: if the plan will actually do what it was supposed to in that given time period
2) Amount: whether the estimated amount will be collected and whether a bunch of people will still go through the toll.

I agree D is okay and probably better. but how to pick C over D given that C weakens the claim if the plan will actually achieve its aim in 5 years

DanTe02, think about this. During that time span between announcement and implementation, no user would go ahead and buy 5 years worth of tokens. They just buy more tokens than usual. I agree that it will put a tiny dent on the plan, but definitely not as big as D where you're straight up losing out on 20% of your target revenue. I doubt that that short span b/w announcement and implementation, would result in that big a dent to the revenue. It would be what, 2 months, 3 months? And it's not as if you won't earn any revenue during that time. People are still going to buy the tokens at the current price, you'll only lose out on the difference between the current price and proposed price, which might also be covered due to the extra sales. Hard to lay it out mathematically, but overall it's not as strong as D.

The Plan: Increase toll on those bridges.
Expectation: Recovery will happen in 5 yrs.

Look, the plan is how to recover the amount. In how much time the recovery will happen is an estimate.
So what we need to focus on is whether increased toll will lead to increase in collection.

Also, note that option (C) says "commuters will postpone the impact". So they will need to pay extra later but for a while they will stay pay the same. It doesn't say that commuters will buy lifetime passes at current rate. It says they can postpone the impact on them (temporarily). But later they will still need to pay extra.

Option (D) clearly says that people switch routes (not temporarily). Then we may actually see less collection.

So the correct option of the two is clear.
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