#19 - Some cleaning fluids, synthetic carpets, wall paneling

[Administrator]

Complete Question Explanation

Must Be True-CE. The correct answer choice is (D)

Answer Choice (A): This answer choice in incorrect. Again, the stimulus tells us nothing about the effects of houseplants on Benzine levels.

Answer Choice (B): From the stimulus we know that certain synthetic products release toxins. This does not mean that all nonsynthetic products must therefore be safe.

Answer Choice (C): The author tells us that well insulated houses trap both heat and toxins, but we have no information about the ability of houseplants to trap heat.

Answer Choice (D): This is the correct answer choice. As we know from the stimulus, “houseplants remove some household toxins from the air and thereby eliminate their danger.”

Answer Choice (E): Although we know that houseplants can help reduce levels of certain toxins in cases of limited ventilation, it is unclear what effects they might have in a house that is well ventilated.

[victorias]

2 questions

1. The passage states that 20 large plants were used in the study and it was found that it eliminated formaldehyde - So is it safe to say that we don't know what the effects on toxins levels would be if we had less or more than 20 plants or if we had smaller plants? Does this mean that there were no effects on the levels of other types of toxins (i.e. it only eliminated formaldehyde)?

2. Can you go over choice E

Thanks

[Laura Carrier]

Hi Victoria,

You are correct to read the information in the stimulus so precisely. We are told that 20 large plants eliminated formaldehyde from a well-insulated house. But you are right that we don’t know what would have happened in different circumstances such as a smaller number or size of plants.

But be careful about your next thought. Knowing that these 20 large plants eliminated formaldehyde doesn’t tell us anything about what additional effects the plants had, so we are just as uncertain about that (if not even more so) as about what effect a different number or size of plants would have had on the formaldehyde. There is no way for us to conclude from the information we have whether there were any effects on the levels of other types of toxins, such as benzene, because we are told only that the formaldehyde was eliminated. So, no, we definitely couldn’t say that there were no effects on the levels of other types of toxins. They simply don't tell us.

As for answer choice (E), one major problem is that it asks us to compare the impact of houseplants on toxins in well-insulated houses versus well-ventilated houses. We do know that the toxins mentioned in the stimulus are “not a problem in well-ventilated houses,” but are “a problem” in at least some well-insulated houses. Although it’s hard to know what “not being a problem” in the well-ventilated houses actually means, it’s possible that well-ventilated houses could, on their own (even without the presence of houseplants) contain fewer toxins than (or the same levels of toxins as) well-insulated houses even with the help of houseplants. Thus, we can’t possibly know that (E) is right that there will be fewer toxins present in the air of a well-insulated house with houseplants than in the air of a well-ventilated house without houseplants.

This answer choice looks worse and worse if we think about it in light of your two earlier questions. First of all, (E) doesn’t specify the number or size of houseplants present in the well-insulated house, so we wouldn’t even know enough about their effect on formaldehyde to speculate that the formaldehyde levels in that house would be lower than in a well-insulated house without houseplants. Second, (E) mentions fewer toxins as a general category, whereas all we know is that houseplants had an effect on formaldehyde, so (E)’s reference to “fewer toxins” is far more broad than the information we actually have about the effect of houseplants. Even if we were to assume (though the stimulus doesn’t give us a basis for doing so) that the well-insulated house with houseplants had no formaldehyde and the well-ventilated house without houseplants did have formaldehyde, we still wouldn’t know anything about the total numbers of toxins present in the air of either house, and thus couldn’t conclude that one or the other had “fewer toxins.”

You are definitely thinking in the right direction. I hope this helps to clarify the details!
Laura

[andriana.caban]

Hi!

Can you explain why/how this stimulus contains causal reasoning? I'm not seeing a cause & effect.

[andriana.caban]

Can I get an answer to my question? I'm not sure exactly why/how this stimulus contains causal reasoning?

[KelseyWoods]

Hi Andriana!

The causal relationship in this stimulus comes from the idea that the houseplants remove some household toxins. So houseplants are a cause of removing toxins (the effect). Remember that causal reasoning won't always include causal indicator language, but it will always include a relationship in which one thing actively makes another thing happen. In this case, the houseplants are actively causing the toxins to be removed, so we know that we have a causal relationship.

Hope this helps!

Best,
Kelsey

[saygracealways]

Hi PowerScore,

I'm wondering if you could please explain why answer choice (D) is correct?

I chose (A) because the passage says "Recent tests demonstrate that houseplants remove some household toxins in the air" (Cause: Houseplants; Effect: Remove some household toxins in the air). Since the first sentence mentions benzene as a toxin, how is it that (A) is unsupported by the stimulus?

My reasoning for crossing out (D) is that the passage says that houseplants are a solution for well-insulated houses that face the problem of trapping the toxins in the first place, but that well-ventilated houses do not face this problem. Thus, I thought that "compensate for some of the negative effects of poor ventilation" was irrelevant because the problem of toxins doesn't even affect ventilated houses.

Hope this makes sense, and thanks much in advance!

[Paul Marsh]

Hi saygracealways!

The stimulus tells us that formaldehyde and benzene are both household toxins. We are then told that houseplants remove "some" household toxins. The final sentence tells us that plants eliminated formaldehyde. So for all we know, the "some" household toxins eliminated could just be formaldehyde. There is nothing in the stimulus to suggest that plants also eliminate benzene. So the passage does not really support (A). Let's take a look at (D).

Thus, I thought that "compensate for some of the negative effects of poor ventilation" was irrelevant because the problem of toxins doesn't even affect ventilated houses.

The stimulus tells us that the problem of toxins doesn't affect well ventilated house. But everything suggests that poorly ventilated homes aren't so lucky! So the information in the stimulus regarding the plants removing toxins from the air suggests that they can compensate for the negative effects of poor ventilation.

Hope that helps!