LSAT Explanation PT 30, S2, Q9: A running track with a hard

LSAT Question Stem

Which one of the following, if true, is evidence that the explanation given above is only a partial one? 

Logical Reasoning Question Type

This is a Flaw question. 

Correct Answer

The correct answer to this question is C. 

LSAT Question Complete Explanation

Let's first analyze the argument in the passage. The passage states that a hard running track leads to greater running speed than a soft one under dry conditions. The reason provided for this is that even though step length is shorter on a hard surface, the time a runner's foot remains in contact with the running surface is less on a hard surface. In this argument, the premise is that the time a runner's foot remains in contact with the running surface is less on a hard surface, and the conclusion is that a hard running track leads to greater running speed than a soft one under dry conditions.

To make this argument more understandable, let's use a simple example. Imagine two runners, one running on a hard surface and the other on a soft surface. The runner on the hard surface will have a shorter step length, but their foot will be in contact with the ground for a shorter period, allowing them to move faster overall.

Now, let's come up with an "Evaluate" question for this argument: "Is there any other reason that a hard running track leads to greater running speed than a soft one?"

The question type of this problem is Flaw, and it asks us to identify evidence that the explanation given in the passage is only a partial one. Let's evaluate each answer choice.

a) Dry running conditions can be guaranteed for indoor track races only.

This answer choice doesn't provide any additional explanation for why a hard surface leads to greater running speed. It only talks about the conditions under which dry running can be guaranteed. So, this answer choice is incorrect.

b) In general, taller runners have greater average step length than shorter runners do.

This answer choice talks about the relationship between a runner's height and their step length, but it doesn't provide any additional explanation for why a hard surface leads to greater running speed. Therefore, this answer choice is incorrect.

c) Hard tracks enhance a runner's speed by making it easier for the runner to maintain a posture that minimizes wind resistance.

This answer choice provides another reason for why a hard surface leads to greater running speed: it allows the runner to maintain a posture that minimizes wind resistance. This suggests that the explanation given in the passage is only a partial one, making this the correct answer.

d) The tracks at which the world's fastest running times have been recorded are located well above sea level, where the air is relatively thin.

This answer choice talks about the location of the tracks with the world's fastest running times, but it doesn't provide any additional explanation for why a hard surface leads to greater running speed. It is unclear whether the tracks mentioned are hard or soft, so this answer choice is incorrect.

e) To remain in top condition, a soft track surface requires different maintenance procedures than does a hard one.

This answer choice talks about the maintenance procedures for soft and hard track surfaces, but it doesn't provide any additional explanation for why a hard surface leads to greater running speed. Therefore, this answer choice is incorrect.

In conclusion, the correct answer is C, as it provides another reason for why a hard surface leads to greater running speed, suggesting that the explanation given in the passage is only a partial one.