LR Question 8 Explanation
QUESTION TEXT: Fluoride enters a region’s groundwater when rain…
QUESTION TYPE: Most Strongly Supported
FACTS:
- Fluoride enters groundwater when rain dissolves minerals in the soil that contain fluoride.
- When all other factors are the same, more fluoride enters groundwater when the soil also has lots of sodium.
ANALYSIS: This stimulus seems complicated, but really there are only two things happening. I simplified the stimulus to two facts.
All we can really conclude is that sodium increases how much fluoride enters the soil during rainfall.
___________
- This has no support. The first sentence tells us that fluoride-bearing minerals are a source of fluoride in groundwater, and the argument doesn’t tell us about any other sources.
- This seems to contradict the first sentence. That sentence says that rainfall causes fluoride to enter groundwater.
- The stimulus doesn’t even mention “sodium-bearing minerals”. This answer is trying to confuse you by making up a term that sounds like “fluoride-bearing minerals” in order to make a comparison the stimulus never made.
- CORRECT. This is very well supported. The first sentence says that dissolution is how fluoride enters groundwater. So if more fluoride enters groundwater when sodium is present, then presumably sodium increases fluoride dissolution.
- Look at the fourth line. Researchers are comparing soils with the same concentration of fluoride-bearing minerals. In soils with higher concentrations of sodium, more fluoride enters groundwater, even though fluoride concentrations are the same.
More Resources for Most Strongly Supported Questions
- Intro Course lesson: This intro course lesson covers Most Strongly Supported questions.
- Mastery Seminar lesson: This LR Mastery seminar lesson covers most strongly supported questions.
I discounted answers (D) & (E) right away because the use of the word “rate.” I was under the impression that “rate” means “velocity” and not “concentration” or “volume.” I picked what was in my mind the best worst answer (A).
-Is my definition of rate in the context of this question incorrect?
-Or, does rate have a separate significance in Newton, PA?
-If the ladder is true, what other words used on the LSAT have specialized meaning?
Thanks for all the help; keep krushing it with your website!
Your interpretation of rate is correct. The stimulus tells us that when rainfall, concentrations of flouride-bearing minerals and other relevant variables are held constant, flouride concentrations are higher in areas containing a high concentration of sodium. So, it’s very likely that the only differentiating factor between areas containing sodium and areas not containing sodium is the rate at which the flouride dissolves. The higher rate of dissolution explains the higher concentration of flouride in the areas containing sodium.