#13 - Researchers have studied the cost-effectiveness of

[Administrator]

Complete Question Explanation

Strengthen. The correct answer choice is (E)

Your task in this Strengthen question is to select the answer choice that most supports the conclusion
that seawater agriculture near sea level should be cost-effective in desert regions although its yields
are smaller than traditional, freshwater agriculture.

Premise: researchers have studied the cost-effectiveness of growing halophytes—salttolerant
plant species—for animal forage

Premise: halophytes require more water than conventional crops, but can be irrigated
with seawater

Premise: pumping seawater into farms near sea level is much cheaper than pumping
freshwater from deep wells

Conclusion: thus, seawater agriculture near sea level should be cost-effective in desert
regions although its yields are small than traditional, freshwater agriculture

A weakness in this argument is that it does not provide sufficient information for you to assess the
impact on cost-effectiveness of pumping seawater to farms. All you know is that it is less expensive
to bring seawater to farms near sea level than it is to pump fresh water from deep wells. However,
this comparison does not tell you about the other costs that may be associated with the proposal. Nor
does it tell you how either expense fits into the overall cost of farming. Without this information, the
conclusion is weak.

The correct answer in this Strengthen question will support the conclusion that seawater agriculture
near sea level in desert regions is cost effective, likely by providing information regarding how the
cost differential between irrigating with sea water rather than fresh water from deep wells affects the
overall cost.

The incorrect answers will not support the conclusion, meaning they either will have no effect on the
conclusion or could undermine it.

Answer choice (A): This choice has no effect on the conclusion, because it does not provide enough
information regarding the difference in nutritional value for you to assess its impact. For example,
from this information you are not able to tell whether the halophytes provide more or less nutritional
value.

Answer choice (B): This choice does not affect the conclusion, because the proposal is based on
irrigating the farms with salt water.

Answer choice (C): Because the argument was constrained to the cost effectiveness of growing
halophytes, and not the profitability of creating the halophyte strains, this choice has no impact on
the conclusion.

Answer choice (D): As with choice (A), this answer does not provide enough information for you to
assess its impact, but rather states only that the costs are “different.”

Answer choice (E): This is the correct answer choice. This choice is correct because it provides
information that permits you to assess the cost of pumping water for irrigation in relation to the other
costs of farming, supporting the inference that the proposal is costs effective.

[15veries]

Hi,
I was not sure how E helps the argument...I chose it in the end but still do not have confidence.
Is it because it says "one of the largest cost"? So it is part/whole issue?
At first actually I eliminated this choice because of this though...

[Jonathan Evans]

Hi, 15veries,

Here's a recap of the argument:

The claim is that seawater agriculture will likely be cost effective in desert regions.

The premise is that pumping seawater is much cheaper than pumping freshwater from deep wells.

The counteracting premise (going against claim) is that halophyte farming has lower yields.

One necessary assumption is that the savings from using seawater will outweigh the loss from lower yields.

Answer choice (E) addresses this assumption with new information that indicates that the costs of pumping fresh water is proportionately very expensive. In other words, dramatically reducing this cost would be likely to offset the lower yields. I hope this helps.

[vedan22]

Hi - can you explain what answer choice E is actually saying? I'm not understanding how this information would be a rebuttal to the counterargument regarding smaller yields, but I think it's mostly because I'm not understanding what it means.

[AthenaDalton]

Hi Vedan,

Thanks for your question! Here's what answer choice (E) is getting at.

The argument is that salt-water farming is more cost-effective than fresh-water farming, even though fresh-water farms produce a greater amount of produce than salt-water farms do. Just for the sake of example, imagine that a fresh-water farm produces 100 units of produce per acre. A salt-water farm produces just 50 units of produce per acre. So how would the salt-water farm be more cost-effective?

If the cost of water makes up a huge portion of producing crops -- for the sake of example let's imagine that water costs account for 80 percent of the farming costs -- then any water savings would yield huge dividends for a farm. So a salt-water farmer that pays $100 to water 1 acre with saltwater and produce 50 units of crops will come out money ahead of a freshwater farmer that pay $1000 to water 1 acre with freshwater and produce 100 units of crops.

I hope that helps clarify things for you. Good luck studying!

Athena

[BostonLawGuy]

I was torn between answer choice A and E. I'm confused as to how volume/yield does not impact the reasoning since we know yields are smaller with plants that are salt-watered.

I can imagine 100 gallons of salt water will yield one measly pound of plant food.
But 1 gallon of fresh water yields 500 pounds of plant food.
Even though the 100 gallons is cheaper per gallon (maybe at $1/gallon) it would still be cost-effective to use fresh water at $2.00.

I was looking for an answer to address what I thought was this weakness in the argument, if indeed it is a weakness. Can anyone shed some light on this?

[Robert Carroll]

BLG,

Answer choice (A) says the nutritional value is different. It doesn't explain how it varies. What if the nutritional value is much lower when animals forage on halophytes? Then that would weaken the argument. I need to know how it's different in order to know how that will affect the argument, and since answer choice (A) fails to clarify the difference, its impact on the argument is unknown.

Robert Carroll

[ericau02]

Hi can you please re explain this, This is so confusing. I don't even know what I'm supposed to strengthen or what the weakness was. What to look for etc? I would not have been able to see this pre phrase of connection of cost on the actual exam. How would I know what to look for in terms of this type of linkage/connection.

[Dave Killoran]

Hi can you please re explain this, This is so confusing. I don't even know what I'm supposed to strengthen or what the weakness was. What to look for etc? I would not have been able to see this pre phrase of connection of cost on the actual exam. How would I know what to look for in terms of this type of linkage/connection.

Hi E,

Thanks for the question. This is definitely a confusing problem, and when you have a difficult stimulus like this, I suggest stepping away for a day or two and then reviewing it a second time since things can look very different after some time away! If it's still unclear, the next step is for you to produce a brief summary of each sentence. You want to make sure that when reading you understand what was said because without that, it's extremely difficult to answer a question about that same information

With the prephrase, it's about connecting premises to the conclusion. And that occurs even if you don't see a huge weakness. Instead, focus on the elements in play. So, what do we have here? Here's a short summary:

• These seawater plants can be given seawater, and that's cheaper than freshwater wells. So, for desert farms near the sea level, it looks like it may be cheaper to pump in seawater even though you get less from it.

The weakness here is the tradeoff at the end between the cheaper seawater and the lower crop yield. Specifically, what if the irrigation part is really a small cost overall? If that's the case, making that part cheaper might not offset the loss in crops due to the lower seawater yield. Answer choice (E) closes that weakness by saying that the irrigation part is a big expense. So, savings on a big expense becomes a lot more likely to be worth it. Not an easy prephrase at all (and one that most people wouldn't make) but it comes from the focus on money and whether this is worth it. It'd basically a relative cost type of problem, where just because something is cheaper doesn't mean that it's the cheapest, or in this case, worth making a change for.

Thanks!

[ericau02]

Thanks Dave this definitely make so much sense, but... and excuse my french here when i say this, but how in the hell would I be able to make such a pre phrase like that. And this frustration is towards the exam itself and the makes not to you by any means. I really have difficulty with these pre phrases I just don't know how I would be able to figure out a question like this on the actual exam day.