Modified Feed Corn

Step 1: Identify the Question

The wording useful to know in order to evaluate in the question stem indicates that this is an Evaluate the Argument question.

Step 2: Deconstruct the Argument

Note: this argument uses the term “feed corn” interchangeably with the word “corn.” Both terms refer to corn that is grown specifically to feed to animals, not humans. Throughout the argument, there are two types of this corn mentioned: ordinary feed corn (OC) and genetically modified feed corn (GMC).

GMC: pest resist; use less insecticide, = yields OC

OC costs less

Savings on I for GMC not more than > costs for GMC

SO: switch to GMC not likely to > prof

The author concludes that switching from OC to GMC is unlikely to increase profits, since a group of farmers who tried switching found that the costs associated with growing GMC frequently exceeded the savings accrued from reduced use of insecticide. This conclusion assumes that there are no additional savings that could be accrued by using GMC, allowing these farmers to increase profits. It also assumes that there are no opportunities for farmers to sell GMC for a higher price, thereby increasing profits. Is that the case?

Step 3: Pause and State the Goal

On Evaluate questions, the answers will be in the form of a question or a “whether x is true” statement. The correct answer will address an issue on which the argument hinges, depending on whether that statement is true: one way, the argument will be strengthened; the other way, the argument will be weakened.

Step 4: Work from Wrong to Right

(A) This choice is confusing. Re-worded, it says “Whether there are some corn pests that can’t be stopped by either regular insecticides or the GMC.” If there are, then both the regular corn and the GMC would be equally affected. If there aren’t, then both types of corn would still be equally affected. This choice does not affect the conclusion, since it does not address the possibility that farmers could increase profits by switching to GMC.

(B) This choice references feed corn in general; it does not make a distinction between GMC and OC. If all prices have remained steady, the argument is not affected. If all prices have fluctuated, the argument is not affected, since any impact on GMC profits would also apply to OC profits.

(C) This choice references feed corn in general; it does not make a distinction between GMC and OC. The price of insecticide for corn vs. the price for other crops is not at issue in the argument.

(D) CORRECT. If the farmers did apply more insecticide than needed, they could reduce the amount of insecticide even more next season. This further reduction could allow them to save enough money to increase profits, so this opportunity weakens the conclusion. If, on the other hand, farmers applied just as much insecticide as needed, then they would have to do the same next season. This necessity would support the argument’s conclusion that the farmers are unlikely to increase profits by growing GMC.

(E) This choice references feed corn in general; it does not make a distinction between GMC and OC. Whether corn in general is more profitable than other crops is not at issue in the argument.
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RanjanSury, I think you've correctly identified the problem with (C):


If choice (C) were, "Whether the insecticides typically used on ordinary feed corn tend to be more expensive than insecticides typically used on genetically modified feed corn," then it might have some bearing on the argument.

Regardless, we are already told that "what these farmers saved on insecticide rarely exceeded their extra costs for seed". If the farmers applied the correct amount of insecticide, then who cares how much the insecticide actually cost? Even if the insecticide for genetically modified corn is cheaper, the savings in insecticide costs do not make up for the additional costs of the genetically modified seed.

However, we would absolutely want to know whether the farmers were applying more insecticide than was actually necessary. If so, they might be able to further reduce their insecticide costs. That would directly affect the evidence cited in the passage, so (D) is the best answer.
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Let's say that most farmers who tried the GM corn applied more insecticide than was actually necessary. In that case, they could theoretically save even MORE money on insecticide by using less of it next time. In other words, they spent more money than was needed on insecticide.

The author says, "The farmers saved X dollars on insecticide, but they had to spend an extra X dollars (approximately) for the GM seed. So overall they did not save any money." But maybe farmers used, for example, twice as much insecticide as was actually necessary. In that case, using the GM seeds with the CORRECT amount of insecticide would actually save the farmers money.

So we would absolutely want to answer the question in option (D) in order to evaluate the author's argument. I hope that helps!
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The argument does not talk about the retail price changing according to the seeds used. So we assume that it stays the same while evaluating our options. If some option tells us that using GM seeds, we can command a higher price for the crop, it is certainly something we should evaluate with reference to the profit. Since the options do not mention it, we do not need to worry about it.
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Hi teaserbae,

Scientists have modified feed corn genetically, increasing its resistance to insect pests. Farmers who tried out the genetically modified corn last season applied less insecticide to their corn fields and still got yields comparable to those they would have gotten with ordinary corn. Ordinary corn seed, however, costs less, and what these farmers saved on insecticide rarely exceeded their extra costs for seed. Therefore, for most feed-corn farmers, switching to genetically modified seed would be unlikely to increase profits. --> Highlighted part is the conclusion


The conclusion is related to profit. We need something to evaluate that part. This choice doesn't impact the profit at all.
A "yes" to the option will mean that there are insects that equally impact modified and normal corns. Thus, as per the premise conclusion still holds.
A "no" to the option will mean that there are insects against which both modified and normal corns are equally effective. Thus, as per the premise conclusion still holds.
In either case the conclusion still holds. Thus, A is wrong.

Hope that helps!
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