GMAT Club Olympics 2025 (Day 1): Civil Engineer: Trade between the

Option E most seriously undermines the engineer’s argument, because if the reliability of existing transportation methods between north and south can be improved without building any freeway, then constructing a new freeway (especially one that must pass within five miles of every city) is neither necessary nor the only way to boost trade. By contrast, A merely relaxes the proximity requirement for a freeway rather than challenging the need for a freeway at all; B points to additional causes of low trade but doesn’t show that better transport wouldn’t help; C highlights budget constraints, which don’t refute the logic that a freeway would improve trade; and D actually supports the idea that closer transport links spur traffic rather than weakening it.

The civil engineer concludes "that we must build a freeway system, connecting the two groups of cities, that passes no more than five miles away from each city". Option A weakens this argument.

A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state.
It just argues about distance (still accepts a freeway is needed).

B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.
The real problem isn't mainly transportation. Even if we fix transport, trade might not improve.

C. The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system.
It talks about money (doesn't challenge the reasoning).

D. Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system with the cities.
It actually supports the argument.

E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system
It offers an alternative (but doesn't deny transport is the issue).

Answer B

Goal:

Plan:

Premises (facts that are given, and therefore cannot be negated):

Assumptions:
(1) Building a freeway system that connects the two cities will directly lead to economic growth and trade ("we must build a freeway system").
(2) There are no other more significant problems to tackle, other than the transportation of goods between these two cities, that caused the stagnant trade between the two cities.
(3) For significant economic growth and trade to occur, the freeway must pass no more than five miles away from each city.

Strategy for Weakening Questions:
To weaken an argument, we can attack the assumptions and look for alternatives that undermine the plan, without negating the premises.

Answer Choices:
A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state.
Notice this option is more lenient than the original argument. After all, if 10 miles is already enough to increase the trade, then the argument's plan, which proposes a freeway within 5 miles of each city, would certainly achieve its goal.

B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.
Correct. Very in line with a direct attack on Assumption (2). If, in fact, B is true, then it can cast considerable doubt on the success rate of the plan, given it is not the most important cause for the lack of trade between the two cities.

C. The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system.
This is a common misdirection in goal/plan type questions. Instead of analyzing the efficacy of the plan, it highlights the difficulty of implementing it. Please do not be misled, as feasibility does not undermine the plan's logical reasoning. We can still have a perfectly well-reasoned plan, and still not have the resources to do it. Focus, instead, on what the question is asking.

D. Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system with the cities.
If this is true, it supports Assumption (1). Therefore, the plan would be in line with tackling that exact issue. This is a strengthening option, not a weakening one.

E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system
Let's consider a scenario in which the argument's reasoning is sound and the plan succeeds. Could other improvements still be made without the freeway system? In other words: could it be that the freeway system tackles 90% of the problem, but improvements could still be found for the remaining 10%?
The answer is yes. We don't need the freeway to solve 100% of the trade stagnation issue. Therefore, E could still hold to be true, while the plan is logically sound and is not affected by it. A clue might be the "to some extent" qualifier, which could still refer to an insignificant amount. Therefore, whereas B indicates that alternatives to the freeway system would address a considerable portion of the problem, option E fails to weaken the argument.

Given,
X- [Trade has stagnated greatly]
Y- [Few reliable methods of transporting goods]

Author concludes that
[Freeway system less than 5 miles] -> Necessary For -> [Spur economic growth in this state]

Options A, C and D have no impact on the conclusion, between B and E:

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B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.

This option directly challenges the logical gap in the argument.
Author makes a jump from
[Few reliable methods] to
[Freeway system less than 5 miles] -> Necessary For -> [Spur economic growth in this state]

Note that the objective is to [Spur economic growth in this state] and the idea that [Freeway system less than 5 miles] is a "must do" is weakened if there are some very big issues other than the few reliable methods. For example, what if the two cities are extremely far away, or transport trucks are banned.

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E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system

Unlike B, I rejected this option because it does not explicitly present a causal relation so has no impact.
Option E just states [Freeway system less than 5 miles] -> Not Necessary for -> [Few reliable methods]

A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade...
✅ Correct.
This directly weakens the engineer’s reasoning that the freeway must pass within five miles. If a 10-mile distance is enough, then the proposed constraint (within 5 miles) is unnecessary, possibly making the plan more expensive and less efficient.

It's the second one because attack the conclusion of the civil engineer.

Premise:

• Trade between cities of 2 area is stagnant
• Lack of transportation methods between them.

Conclusion: Build freeway system between cities (within 5km away from each) => Economic growth
Unstated assumption: If more transportation methods (i.e: freeway system), trade will flow, economic will growth.

WEAKEN the conclusion by breaking the link:

• More transportation methods/freeway system does necessarily not lead to increasing trade/economic growth.

A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state.
=> Supports the plan but weakens slightly engineer's proposal (10 miles is enough instead of 5 miles as proposed). DOES NOT BREAK the assumption. More transportation methods still lead to economic growth. DOES NOT WEAKEN.

B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.
=> Attacks the assumption of more transportation/building freeway will lead to more trade by stating there're OTHER more serious causes behind lack of trade. So, more transportation or building freeway doesn't mean trade/economy will grow. WEAKENS.

C. The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system.
=> Out of scope. Budget is not within the scope of the argument. Even if they lack budget, it's possible if they can raise fund elsewhere and the plan can still succeed. DOES NOT WEAKEN.

D. Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system with the cities.
=> More transportation, more growth in commerce => more economic growth. This strengthens the argument. DOES NOT WEAKEN.

E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system
=> Rejects engineer's plan of building freeway by offering an alternative plan but mentions nothing about the result whether trade or economic growth will grow or not. Cannot break the argument. DOES NOT WEAKEN.

Conclusion:To spur economic growth and increase trade between the northern and southern cities, a freeway must be built that passes no more than five miles from each city.

Underlying Assumption:Only a freeway within five miles of each city will sufficiently increase trade.

Task:To find the option that most seriously weakens this reasoning — showing the proposed five-mile limit is unnecessary or ineffective.

A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state- If a freeway within ten miles and not five miles, is sufficient to increase trade, the engineer’s specific proposal is unnecessarily restrictive and possibly wasteful.
Option A is correct as this seriously weakens.

B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities -
This challenges the broader strategy but doesn’t directly undermine the reasoning for the five-mile freeway plan.

C. The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system - This introduces a financial obstacle but does not weaken the logic of the proposed solution itself.

D. Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system with the cities - This actually supports the idea that proximity (like within five miles) improves trade, thus strengthening the civil engineer’s argument.

E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system - This suggests an alternative solution but doesn’t directly refute the idea that a freeway within five miles would help trade.

Answer: A.

Only option A directly undermines the need for the freeway to be within five miles of each city, thus most seriously weakening the civil engineer's reasoning.

A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state.
It weakens the specific distance requirement (5 miles) but still agrees a freeway is needed.

B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.
It destroys the core assumption that bad transport is the problem. Even if you build the freeway, trade might not improve.

C. The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system.
It talks about money It doesn't challenge whether the freeway would work.

D. Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system with the cities.
It supports the engineer's position. It confirms closer freeways help trade.

E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system
It offers an another solution, but doesn't deny that better transport would help trade.

Correct answer is B

Problem: Trade between northern and southern cities is stagnating.
Cause (according to engineer): Lack of reliable transportation methods.
Solution: Build a freeway that passes within five miles of each city to increase trade.

A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state.
If a freeway 10 miles away is just as effective, then the specific requirement of "within 5 miles" is unnecessary — undermining the plan’s logic.

B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.
This option says that lack of reliable methods of transportation is also a cause, which means the solution suggested could have a positive impact on the trade, even though there might be better or more efficient ways.

C. The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system.
This talks about feasibility of the plan. Please note that a plan can be both necessary and not feasible at the same time.

D. Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system with the cities.
This supports the argument.

E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system.
Just because there are other ways to deal with a problem doesn't mean that the suggested plan will not work.

ANs: B

Because this undermines the core assumption that a freeway alone will spur economic growth

Answer is A.

Civil Engineer: Trade between the northern and southern cities of our state has stagnated greatly. There are few reliable methods of transporting goods between these two groups of cities, so in order to spur economic growth in this state, we must build a freeway system, connecting the two groups of cities, that passes no more than five miles away from each city.

Which of the following, if true, most seriously weakens the civil engineer’s reasoning?

A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state.
B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.
C. The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system.
D. Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system with the cities.
E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system


A -> If true, this weakens the engineer's reasoning that the freeway system needs to be 5 miles away.

B -> Sure, there may be other important causes, but it doesn't weaken the engineer's reasoning that the freeway system at 5 miles away will boost trade.

C -> The passage only talks about an engineer's reasoning of the need of a freeway system. It's financial sense is not established.

D -> This does not talk about relation between trade & the freeway system. Irrelevant point

E -> Sure there may be other ways to increase trade between the two regions, but t doesn't negate the engineer's reasoning that the freeway system at 5 miles away will boost trade.

A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state.
This suggests the engineer is being too strict about the 5-mile rule. It still agrees the need of building a freeway system.

B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.
It introduces superior alternative causes. It renders the transport-focused solution potentially irrelevant.

C. The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system.
It concerns implementation constraints. It is irrelevant with the reasoning.

D. Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system with the cities.
It supports the proximity-trade relationship. It strengthens rather than weakens.

E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system
It proposes alternative solutions. It maintains transport as the key variable.

The right answer is B

Answer: B

Why choice B most seriously weakens the reasoning
The engineer’s argument rests on a chain of logic:

1. Trade is stagnant because there are too few reliable ways to transport goods.
2. Therefore, building a freeway (within five miles of every city) is necessary to spur growth.

Choice B states that other, more important factors—not transport reliability—are chiefly to blame for the low trade level.
If the main obstacles lie elsewhere (e.g., tariffs, demand, or supply issues), a new freeway might leave trade largely unchanged. That directly undercuts the causal link the engineer relies on, so it is the strongest weaken-er.

Premises:

• Trade between northern and southern cities has stagnated.
• There are few reliable methods of transporting goods between them. (reason)

Conclusion:
To spur economic growth, we must build a freeway system that passes no more than five miles away from each city.

A. Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state.
If a freeway 10 miles away is sufficient, the specific plan to build one within 5 miles is unnecessary, but this option only weakens the details of the plan, but not the reasoning that a freeway is necessary for trade

B. There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.
If transportation isn’t the main problem, then building a freeway won’t solve the core issue.
This directly attacks the argument’s logic that freeway construction must be done to spur economic growth
Keep

C. The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system.
The option talks about the feasibility of the plan; we should be checking if the plan works or not, so out.

D. Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system to the cities.
more of a strengthener, so out.

E. The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system
the freeway might still be required for significant impact

Conclusion:
Building Freeway system > Increased Trade between northern and southern cities

Weaking Scenario:
There are other reasons which is restricting the trade
Lack of reliable transport system is not the reason behind stagnant trade

IMO Answer B