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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