LSAT 158 | Section 4 | Logical Reasoning: Q11

LR Question 11 Explanation

QUESTION TEXT: In the past, infants who were not breast-fed were fed cow’s milk…

QUESTION TYPE: Most Strongly Supported

FACTS:

1. Doctors said to boil cow’s milk before feeding it to babies.
2. Then scurvy increased among infants. Scurvy is caused by a deficiency in vitamin C.
3. Breast-fed infants didn’t get scurvy.

ANALYSIS: Obviously there is something different between boiled cow’s milk and a human mother’s milk. This difference must be related to the amount or bioavailability of vitamin C, lack of which determines whether or not an infant would come down with scurvy.

___________

1. CORRECT. These facts taken together support the idea that boiling cow’s milk reduces the amount of vitamin C the infants get, compared to drinking mother’s milk.
2. We only know about infants who consumed boiled cow’s milk and those who consumed mother’s milk. We don’t know anything about infants who drank unboiled cow’s milk. It’s possible that fatal infections were rare, but doctors still recommended boiling milk because it could nonetheless save lives.
3. We don’t know this from the facts in the stimulus. Also, mother’s milk comes straight from within the body, so there is less time for bacteria to grow compared to cow’s milk, which is stored.
4. What the doctors know or didn’t know isn’t relevant for our analysis. The conclusion is only about what happened, not what doctors believed.
5. Irrelevant. We don’t know the percentage of mothers who didn’t breastfeed their infants. We don’t know if it is “most”. And it doesn’t matter: the stimulus is only about what happened in the cow’s milk group. The size of the group is irrelevant.

Recap: The question begins with “In the past, infants who were not breast-fed were fed cow’s milk”. It is a Most Strongly Supported question. Learn how to master LSAT MSS questions on the LSAT Logical Reasoning question types page.