#12 - Most adults in country X consume an increasing

[Administrator]

Complete Question Explanation

Must be True-#%. The correct answer choice is (B)

This is one of the LSAT writers' favorite types of questions — the dichotomy between percentages and overall numbers. In this stimulus, we learn that while the adults in country X consume more fat as they grow older, the percentage of fat in their diet stays the same. This type of question should almost always be one that you can prephrase in your head. This is a must be true question. Therefore, we can predict that since the overall amount of fat is increasing while the percentage in relation to overall diet is staying the same, the overall diet must be increasing as well. For example, assume the average adult used to consume 10 pounds of fat a week as part of a diet that included 50 pounds of food overall. Now assume that the same adult is now consuming 20 pounds of fat a week. In order for the percentage of fat to overall diet to stay the same, that adult must now have a diet that includes 100 pounds of food.

Answer Choice (A): The stimulus provides no information that would allow us to compare the fat intake of country X to that of other countries.

Answer Choice (B): This is the correct answer choice. By prephrasing in your head that the correct answer choice must address an increase in the overall diet, you should be able to find this answer choice quickly.

Answer Choice (C): The stimulus tells us that the percentage of fat stays constant as people in country X get older. There is no information in the stimulus that would support this answer choice.

Answer Choice (D): Once again, there is no information in the stimulus that would support this answer choice. We only know that the overall fat and overall amount of food in the diet have increased. We know nothing about the variety of the food in their diet.

Answer Choice (E): Based upon the information provided in the stimulus, this seems extremely unlikely. The combination of increased fat and increased food (not to mention the decreased metabolism of old age) has likely led to some rather large adults in country X.

[LSAT2018]

Are there any general rules for Must Be True questions that involve both numbers and percentages? It gets very confusing sometimes especially when the stimulus gets long and making calculations during the test is too time-consuming...

[Malila Robinson]

Hi LSAT 2018,
In general with any # & % question you want to look at what they are telling you and what they are not telling you. If they are only giving you info about # in the premises but then conclude about a %, there is a problem (and vice versa). Make sure you are looking for 3 parts: The number, the percent & the total. In most questions the total is left out. (So saying that you have 99% of something sounds good until you find out the total is $1.00. Likewise, being told that you have been given 50 free raffle tickets to win a car sounds great, until they tell you that there were millions of tickets given out.

For MBT questions, if they only tell you about the number do not choose an answer about percents (and vice versa).
Hope that helps!
-Malila

[abullard]

The explanation says there is nothing in the stimulus that suggests that C is true. However, I would like to argue that if the percentage of fat in a person’s diet stays the same throughout adult life, it stands to reason that they generally have diets that contain a lower percentage of fat than do the diets of children in country X. Please explain further how answer choice C is incorrect.

I swayed between B and C, but chose C because I always choose the wrong answer when there are two choices and I can't figure out why.

[Luke Haqq]

Hi abullard!

This is a must be true question, so we want something that we know is directly supported by material in the stimulus. Note that there's nothing in the stimulus that gives us any information about the amount or percentage of fat in the diets of children in country X. That is why we can eliminate answer choice (C). It's something that perhaps could be true, but it isn't required to be true based off the stimulus alone.