LSAT 103 | Section 3 | Logical Reasoning: Q19

LR Question 19 Explanation

QUESTION TEXT: Over the past 20 years, skiing has become a relatively…

QUESTION TYPE: Flawed Reasoning

CONCLUSION: Not every skiing injury has decreased in frequency.

REASONING: There are many fewer broken legs and ankle injuries. But knee injuries have increased in proportion to all skiing injuries.

ANALYSIS: This is a classic LSAT distinction: rate vs. amount. The amount of knee injuries could have gone done even though their percentage of the total went up.

How? Well, suppose there were 200 knee injuries in one year, and 10,000 broken legs.

Then assume that leg injuries decline to 100, while knee injuries also decline to 100.

Now knee injuries are half of all injuries, even though there are fewer knee injuries.

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1. The argument never said there were no other types of ski injuries. It just said some types of injuries went down and others went up, and gave examples.
2. The same cause can have multiple effects. New equipment might reduce broken legs but also cause more knee injuries, for example.
3. This is a problem with the argument, but it’s not the main problem. You should always adjust the number of injuries for the number of skiers.
    
   But the argument isn’t hurt by this failure. If the number of skiers went up, then it’s even more impressive that the number of injuries went down. And the increase in knee injuries is given as a percentage, so it’s not affected by the increased number of skiers.
4. CORRECT. See the explanation above. If knee injuries drop but other injuries drop even more, then the proportion of knee injuries increases.
5. The argument says that a couple of categories had larger decreases than the overall average. It never says that all categories fell faster than the overall average (which is impossible, of course).

Recap: The question begins with “Over the past 20 years, skiing has become a relatively”. It is a Flawed Reasoning question. Learn how to master LSAT Flaw questions on the LSAT Logical Reasoning question types page.