LSAT 150 – Section 3 – Question 19

LSAT 150 - Section 3 - Question 19

June 2018

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Question QuickView	Type	Tags	Answer Choices	Curve	Question Difficulty	Psg/Game/S Difficulty	Explanation
PT150 S3 Q19	+LR	Weaken +Weak Causal Reasoning +CausR Net Effect +NetEff	A 33% 166 B 55% 161 C 5% 156 D 1% 155 E 6% 159	160 169 179	+Hardest	148.057 +SubsectionMedium

Weaken

Henry says that electric engines (cars) pollute less than combustion engines. Therefore, switching from regular cars to electric cars would reduce urban pollution.

This isn't a terrible argument. Car engines are a major contribution to pollution. But, Henry hasn't given an exhaustive (hehe) account of the situation. What if the production of electric engines is way more polluting than the production combustion engines? Sure using electric engines is less pollution but you gotta make them in the first place and that could tip the scales.

Umit doesn't go there, though he could have. He brings up another consideration that Henry overlooked. He reminds us that electric engines run on batteries that need charging. Charging all those batteries places greater demand on power plants which then will generate more pollution as a result.

Okay, yeah, that's a good point Umit! You did a good weakening on Henry's argument by pointing out something Henry overlooked (i.e. assumed wasn't an issue). Henry, batteries don't power themselves okay? You gotta charge them you dodo!

Alright, so now we have to do another 180 and weaken Umit's argument. We have to see that Umit assumed that the extra pollution generated by the power plants is relevant. (A) gives us a reason to think that it's not relevant. If it's true that power plants are not near major cities, then does their pollution even matter? Henry was only concerned about urban pollution after all, not pollution in the entire country or on the whole planet. (A) may as well have told us that these power plants are on Mars.

(B) is an attractive trap. It says that the additional units of pollution from the power plants would be "offset" by the decreased units of pollution from the electric engine cars. Okay, "offset" by how much? Entirely offset? Or just somewhat offset? We're not sure. So it could be on a range anywhere from entirely offset to just somewhat offset. But anywhere on that range is bad for Henry. Even if it's entirely offset, then that just means switching to electric cars is no better than not switching in the first place. Henry actually needs switching to electric cars to be better for urban pollution. Not just neutral.

What (B) needed to say is that the additional additional units of pollution from the power plants is only a tiny fraction of the total decreased units of pollution from the electric engine cars. In other words, power plants are generating +1 unit of pollution but electric cars are saving -10 units of pollution. That would help Henry and hurt Umit.

Henry: Engines powered by electricity from batteries cause less pollution than internal combustion engines. Therefore, to reduce urban pollution, we should replace standard automobiles with battery-powered vehicles.

Umit: I disagree. Battery-powered vehicles have very short ranges and must be recharged often. Their widespread use would create a greater demand for electricity generated by power plants, which are themselves a major source of pollution.

Summarize Argument

Umit concludes that we should not replace standard cars with battery-powered cars in order to reduce urban pollution. This is because the widespread use of battery-powered cars would create a greater demand for electricity from power plants, and power plants are a major source of pollution.

Notable Assumptions

Umit assumes that the pollution produced by power plants would affect urban areas (as opposed to affecting only non-urban areas). Umit also assumes that the decrease in urban pollution resulting from switching to battery-powered cars would not outweigh whatever increase in urban pollution is caused by the increased use of power plants.

Pollution caused by power plants is generally confined to a small number of locations a significant distance from major cities.

This provides a reason to think that the pollution from power plants would not necessarily affect urban areas. Thus, Umit’s point about pollution from power plants does not necessarily show that battery-powered cars can’t reduce urban pollution.

The increased air pollution resulting from a greater demand for electricity would be offset by the reduction in air pollution emitted by electric vehicles.

Even if the increased pollution from electricity demand would be offset by decreased pollution from electric cars, that just means we’re back to the same level of pollution as before. This doesn’t undermine Umit’s point, which is that electric cars won’t decrease urban pollution.

Electric motors could be restricted to lighter vehicles such as compact cars, which have smaller batteries and therefore require less power to charge than do the larger batteries needed to power larger vehicles.

Even if electric cars could be limited to smaller batteries, that doesn’t change the fact that widespread use of electric cars would create a greater demand for electricity from power plants.

Hybrid vehicles using both electric and gasoline power moderate the increased demand for electricity produced by power plants.

The argument concerns widespread use of battery-powered vehicles. Hybrid vehicles are a different kind of vehicle and don’t impact what would happen if non-hybrid electrics become widespread.

Most power plants are currently operating well below capacity and could therefore accommodate the increased demand for electricity.

The issue is not whether the power plants could produce enough electricity. It’s about the pollution produced from the power plants. If anything, (E) might strengthen by showing that power plants have the capacity to make more electricity and thus pollute.

LSAT 150 – Section 3 – Question 19

LSAT 150 - Section 3 - Question 19

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LSAT PrepTest 150 Explanations

Section 1 - Reading Comprehension

Section 2 - Logical Reasoning

Section 3 - Logical Reasoning

Section 4 - Reading Comprehension

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