#14 - The axis of Earth's daily rotation is tilted with

[abtinghz]

Hi abtinghz!

Thanks for your questions! You're correct, "without" is an indicator of a necessary condition! When we see the word "without", we utilize the Unless Equation. In this equation, one takes the steps you mentioned, which are to make the term modified by "without" the necessary condition, then negate the remaining term and make it the sufficient condition. Thus, we can see why PCE is the sufficient condition; the phrase "stables and moderate axis tilt" becomes the necessary condition since it is modified by "without" and the remaining part of the phrase "planet's climate is too extreme and unable to support life" is negated (becoming PCE) and becomes the sufficient condition. This gets us the same diagram as mentioned in the quoted comment!

Regarding the last sentence, while you're correct that "only" can be an indicator, there's no conditional logic in the last sentence as there is no connection to another condition. Additionally, it's not relevant to the answer so it's unnecessary to diagram!

I hope this helps
Kate

Hi abtinghz!

Thanks for your questions! You're correct, "without" is an indicator of a necessary condition! When we see the word "without", we utilize the Unless Equation. In this equation, one takes the steps you mentioned, which are to make the term modified by "without" the necessary condition, then negate the remaining term and make it the sufficient condition. Thus, we can see why PCE is the sufficient condition; the phrase "stables and moderate axis tilt" becomes the necessary condition since it is modified by "without" and the remaining part of the phrase "planet's climate is too extreme and unable to support life" is negated (becoming PCE) and becomes the sufficient condition. This gets us the same diagram as mentioned in the quoted comment!

Regarding the last sentence, while you're correct that "only" can be an indicator, there's no conditional logic in the last sentence as there is no connection to another condition. Additionally, it's not relevant to the answer so it's unnecessary to diagram!

I hope this helps
Kate

Complete Question Explanation

Must be true. The correct answer choice is (B)

The two sentences produce the following conditional relationships, which can be linked:


AS = angle stable
GI = gravitational influence of Earth’s large, nearby Moon
PCE = planet’s climate too extreme and unstable to support life

Sentence 2: AS GI
Sentence 3: PCE AS
Chain: PCE AS GI


Again, consider the answers that are most likely to appear in a problem like this: either the chain inference PCE GI, or the contrapositive of that chain inference, GI PCE.

Answer choice (A): This incorrect answer is the Mistaken Reversal of the chain inference. The diagram for this answer choice would be as follows, with the sub-M indicating Mars:


GIM PCEM


Answer choice (B): This is the correct answer. As expected, this is the contrapositive of the chain inference.

Answer choice (C): This incorrect answer is the Mistaken Reversal of the third sentence, and is diagrammed as follows:


AS PCE


Answer choice (D): This answer discusses issues that were not raised in the stimulus, and is thus incorrect.

Answer choice (E): The stimulus indicates that Earth’s large Moon has been necessary for the stable angle of Earth’s tilt, and this stable angle has been necessary for a climate that can support life. Mars, with many small moons, tilts at fluctuating angles and cannot support life. The key difference is that Earth’s Moon is large, and that creates a greater gravitational influence. It is possible, therefore, that a planet with more than one moon could have a stable angle as long as at least one of the moons was of sufficient size (in Mars’ case, the stimulus indicates each moon is small). Thus, it is possible that a planet can have more than one moon and support life. This scenario is contrary to the answer choice, and thus this answer is incorrect.

Note, this question appears in the Logical Reasoning Bible, and thus it has also been discussed multiple times on this Forum. For further discussions, please visit:

lsat/viewtopic.php?t=27721

lsat/viewtopic.php?t=10839

lsat/viewtopic.php?t=1868

lsat/viewtopic.php?t=28794

Hi abtinghz!

Thanks for your questions! You're correct, "without" is an indicator of a necessary condition! When we see the word "without", we utilize the Unless Equation. In this equation, one takes the steps you mentioned, which are to make the term modified by "without" the necessary condition, then negate the remaining term and make it the sufficient condition. Thus, we can see why PCE is the sufficient condition; the phrase "stables and moderate axis tilt" becomes the necessary condition since it is modified by "without" and the remaining part of the phrase "planet's climate is too extreme and unable to support life" is negated (becoming PCE) and becomes the sufficient condition. This gets us the same diagram as mentioned in the quoted comment!

Regarding the last sentence, while you're correct that "only" can be an indicator, there's no conditional logic in the last sentence as there is no connection to another condition. Additionally, it's not relevant to the answer so it's unnecessary to diagram!

I hope this helps
Kate

Hi Kate. Yes thank you so much. I guess Im just having trouble indicating where to make logical connections and such (In regards to the last sentence). This being said, I feel stuck as far as finding the appropriate situations to make conditional diagraming because I cannot seem to identify when it is appropriate to do so and when its not. But I'm blaming everything on being so new to LSAT studies and Im hoping that this feeling of "being lost" will improve with time.