#12 - Many nurseries sell fruit trees that they label

[Administrator]

Complete Question Explanation

Must Be True—SN. The correct answer choice is (E)

The stimulus establishes that some nurseries label Stark Sweet Melody nectarine trees as “miniature” while others do not. In addition, if a variety of fruit tree is not suitable for growing in a tub or a pot, it cannot be correctly labeled “miniature.” The contrapositive of this statement shows that if a tree is correctly labeled “miniature,” then it must be suitable for growing in a tub or a pot:

• Correctly labeled “miniature” Suitable for growing in a tub or pot

The stimulus does not provide any information as to whether Stark Sweet Melody nectarine trees are suitable for growing in a tub or pot. Therefore, there is not enough information in the stimulus to determine whether any of these Stark Sweet Melody trees are correctly labeled “miniature.”

Answer Choice (A): This statement is unknown based on the facts. We only know that some nurseries label Stark Sweet Melody nectarine trees as “miniature.” However, since we do not know whether Stark Sweet Melody trees can be grown in a tub or pot, we have no idea whether these trees are correctly labeled. Therefore, we do not know whether most nurseries mislabel some of their fruit trees.

Answer Choice (B): This answer choice is an Opposite Answer. The only way a nursery can correctly label a tree “miniature” is if it is suitable for growing in a tub or pot. This answer choice states the only way some nurseries label their trees “miniature” is if the trees are unsuitable for growing in a tub or a pot.

Answer Choice (C): This answer choice is similar to answer choice (A) in that there is not enough information in the stimulus to determine whether Stark Sweet Melody trees are correctly labeled “miniature.” Without additional information about whether Stark Sweet Melody trees can be grown in tubs or pots, this answer choice is unknown.

Answer Choice (D): The stimulus provides no information about the nectarine trees that are not labeled “miniature.” The conditional rule in the last sentence of the stimulus provides a standard for when it is correct to actually label a tree “miniature.” This test provides no information about when it is correct not to label a tree “miniature.”

Answer Choice (E): This is the correct answer choice. Using the Unless Equation, this answer choice can be translated as, “if all nurseries correctly label Stark Sweet Melody trees, then the trees must be suitable for growing in tubs or pots.” Note that the logical opposite of “some nurseries mislabel” is “all nurseries correctly label.” Since some nurseries do label their Stark Sweet Melody trees “miniature”, for this labeling to be correct it is necessary that the Stark Sweet Melody variety be suitable for growing in tubs or pots.

[timm2985]

I would appreciate ANY help on this problem!


Question 12: Anyone that could clarify and/or help me understand the answer choices would be much appreciated. I understand how unless statements work in conditional logic. However, I seem to get stumped on connecting them to the premise logic. This is because the correct answer choice connects a specific occurrence from the premise to the final conditional logic statement (which, due to its much more powerful and encompassing nature compared to the other conditional logic statements in the premise, I assumed to be utilized in the correct answer in connection with one of the other less powerful logic statements). Again, if anyone knows a similar question, please let me know where to find it.

[Ron Gore]

Hi, Tim! Welcome to the PowerScore forum.

The question concerning which you've asked is a Must Be True question. As we discuss in greater detail in the Logical Reasoning Bible, an important distinction between a Must Be True question and most other question types is that you typically will not see a conclusion within a Must Be True stimulus. I infer from your question that you believe the final sentence of the stimulus to be a conclusion derived from one of the prior sentences, which you take to be the premises, all of which are conditional. Those views are incorrect, however.

The stimulus contains a set of four facts. The first three sentences are not conditional statements, because they are no absolute. Instead, they reference only part of a group, and are examples of formal logic. The final statement, which provides an absolute relationship, is conditional.

The Prephrase for the correct answer in Must Be True question is that it will be either a restatement of one of the facts in the stimulus, or that it will be an inference permissible from a combination of the facts. More specifically, when the Must Be True stimulus contains a conditional relationship, your Prephrase is that the correct answer choice is most likely the contrapositive of the conditional relationship in the stimulus. And, if this stimulus contains more than one conditional relationship, and those relationships can be chained together, the correct answer will typically test on that. Further, the incorrect answers in a Must Be True stimulus containing conditional reasoning will typically include at least one Mistaken Reversal.

In this case, the conditional relationship in the last sentence is "if a variety of fruit tree is not suitable for growing in a tub or a pot, no tree of that variety can be correctly labeled "miniature."' This relationship could be diagrammed as:

suitable for growing tub/pot correctly labeled miniature

Answer choice (E), the correct answer, presents the contrapositive of this relationship, and does so using an "unless" statement and referring specifically to the Start Sweet Melody variety: "unless the Stark Sweet Melody variety of nectarine tree is suitable for growing in a tub or a pot, some nurseries mislabel this variety of tree." This statement could be diagrammed as:

correctly labeled miniatureswm suitable for growing tub/potswm

Answer choice (E) is not drawing an inference from the connection of the third stimulus sentence to the fourth, but rather is applying the conditional rule contained entirely within the fourth sentence, doing so in the case of a tree that was mentioned in the third sentence.

Answer choice (A) is incorrect because it involves an error of formal logic and a reliance on facts not in the stimulus. In the stimulus, we were told that "many" nurseries do one thing, and that "some" nurseries do another. However, we weren't told what percentage or numbers of nurseries do either, so "most" is not supported. Nor is it inherently contained in "some" or "many", nor is it a properly inferred reversal of either term. For you to select answer choice (A), you would need more detailed information regarding the numbers of nurseries who identify their trees in these ways.

Answer choice (B) is presents a conditional relationship that could be diagrammed as:

at least one correctly labeledswm suitable for growing tub/potswm

In other words, this answer choice says that in order for at least one nursery to have correctly labeled this type of tree, then the variety must not be a miniature. This answer choice implies that all nurseries have labeled the tree as not being miniature, which is inconsistent with the passage.

Answer choice (C) says that any variety of tree labeled miniature is labeled incorrectly, implying there are no trees of that variety that are miniature. The facts in the stimulus do not provide us enough information to determine whether or not there are, in fact, any trees of this variety that are miniature. So this choice requires information not provided by the stimulus and thus fails the Fact Test.

Answer choice (D) is requires information about a broader category of tree than discussed in the stimulus (i.e., nectarine trees generally), and so is incorrect.

I hope all of this helps, Tim. As to other questions of this type, any Must Be True question that has conditional reasoning in it will follow a similar pattern regarding your Prephrase and the correct answer choice. In fact, Question 3 from the first logical reasoning section in the same test has the same Prephrase approach.

Thanks,

Ron

[carnegie49]

Hi,

With regard to answer choice B, Ron earlier wrote (emphasis added):

Answer choice (B) is presents a conditional relationship that could be diagrammed as:

at least one correctly labeledswm suitable for growing tub/potswm

In other words, this answer choice says that in order for at least one nursery to have correctly labeled this type of tree, then the variety must not be a miniature. This answer choice implies that all nurseries have labeled the tree as not being miniature, which is inconsistent with the passage.

My Question:

How does the answer choice imply that ALL nurseries have labeled trees as not being miniature?

We do know from the stimulus that at least SOME nurseries do NOT label SSM trees as miniature.

From my reading of it, answer choice B merely requires that there exist some SSM trees that are NOT miniature--however; the stimulus does NOT provide any evidence as to whether this is true or not; the actual type of trees in existence in the nurseries--miniature or not--is not explicitly stated.

Is this correct? Many thanks!!

[Nikki Siclunov]

Hi carnegie49,

This is tricky indeed, and upon reading Ron's explanation of answer choice (B), I think some further elaboration is in order.

Here's what we know:

1. Some nurseries label SSM as "mini." Others do not.
2. Correct label of "Mini" Suitable for growing in a tub/pot.

Obviously, not all nurseries can be correct in their labeling practices, unless there are subspecies of the SSM, some of which can be grown in a tub and others that cannot. We have no evidence that such a possibility exists, so clearly some of the nurseries mislabeled the SSM. This does not mean, however, that some nurseries have correctly labeled SSM. Even if the variety is suitable for growing in a tub or a pot, that doesn't automatically mean that the "mini" label is correctly applied to that variety! To conclude otherwise would be to make a Mistaken Reversal of the last sentence.

Answer choice (B) implies that if a nursery correctly labeled the SSM (presumably, as "non-mini"), then the variety is NOT suitable for growing in a tub/pot. If a variety is not suitable for growing in a tub/pot, then that variety is clearly "non-mini." However, that does not mean that if a variety is "non-mini," then it is unsuitable for growing in a tub/pot - this would be a Mistaken Reversal of our inference.

Does this make sense?

Thanks!