LSAT 122 | Section 1 | Logical Reasoning: Q2

LR Question 2 Explanation

QUESTION TEXT: A study of plaque buildup on teeth used three randomly assigned…

QUESTION TYPE: Most Helps to Explain

ANALYSIS: We have two factors:

1. Whether the brush was sterilized
2. Whether the brush was replaced each month

We are fortunate in that we have control groups. Sterilization made no difference between the first and the second group; it is unlikely to be a factor. Replacing the toothbrush did seem to help the third group.

___________

1. If this is true, it is strange that the second group did not experience better results.
2. CORRECT. This explains why the third group did better: they were the only ones who changed their toothbrushes.
3. Since all three groups were measured by this method, it shouldn’t affect anything.
4. Since the study looked at plaque buildup, it shouldn’t make any difference what the groups did in the past. Further, “some” doesn’t tell us much about how many did this in Group 3 compared to the other groups.
5. This tells us the study controlled this variable well, but it doesn’t explain anything.

Recap: The question begins with “A study of plaque buildup on teeth used three randomly assigned”. It is a Paradox question. Learn more about LSAT Paradox questions in our guide to LSAT Logical Reasoning question types.