LSAT Explanation PT 30, S4, Q19: Birds need so much food energy

LSAT Question Stem

The argument relies on which one of the following questionable assumptions? 

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 break down the argument in the passage. The passage discusses birds and their food energy requirements. It states that some birds spend most of their time eating to maintain their body temperatures. The argument then compares a seed-eating bird and a nectar-eating bird with the same overall energy requirement. It claims that the seed-eating bird would spend more time eating than the nectar-eating bird because a given amount of nectar provides more energy than the same amount of seeds. Here, we have a premise (a given amount of nectar provides more energy than the same amount of seeds) and a conclusion (the seed-eating bird spends more time eating than the nectar-eating bird).

To better understand this argument, let's use a simple example. Imagine you and a friend need to consume 100 units of energy. You can eat apples that provide 10 units of energy each, and your friend can eat oranges that provide 20 units of energy each. The argument is saying that since oranges provide more energy per fruit, your friend will spend less time eating than you.

An "Evaluate" question for this argument could be: "Does it take the same amount of time to eat a given amount of seeds and nectar?"

Now, let's move on to the question type and answer choices. The question is a Flaw question, asking us to identify the questionable assumption the argument relies on. Let's analyze each answer choice:

a) This answer choice is not relevant to the argument because it is already stated that the birds in question have the same overall energy requirements.

b) This answer choice is also irrelevant because it doesn't affect the comparison between seed-eating and nectar-eating birds when it comes to time spent eating.

c) This answer choice is correct. The argument assumes that the time it takes for the nectar-eating bird to eat a given amount of nectar is not longer than the time it takes the seed-eating bird to eat the same amount of seeds. If this assumption is false, the conclusion that the seed-eating bird spends more time eating would not necessarily hold.

d) This answer choice is not a necessary assumption because the energy requirements are the same, and the body temperature is not a factor in the comparison of time spent eating.

e) This answer choice is not relevant because the argument is strictly about comparing energy requirements and the energy provided by different types of food. The factors listed in this answer choice do not affect the argument's validity.

In conclusion, the correct answer is C, as it identifies the questionable assumption that the argument relies on. The argument assumes that the time it takes for the nectar-eating bird to eat a given amount of nectar is not longer than the time it takes the seed-eating bird to eat the same amount of seeds. This assumption is crucial for the conclusion that the seed-eating bird spends more time eating than the nectar-eating bird.