LSAT 119 | Section 4 | Logical Reasoning: Q17

LR Question 17 Explanation

QUESTION TEXT: Researcher: Hard water contains more calcium and magnesium than…

QUESTION TYPE: Weaken

CONCLUSION: People who drink soft water have an increased risk of stroke, etc.

REASONING: People who are treated for heart diseases have less magnesium, and soft water contains less magnesium than hard water.

ANALYSIS: This raises many questions:

1. How much less magnesium does soft water contain?
2. Is the level of magnesium in either type of water high enough to make a difference?
3. Do we absorb magnesium from water? Are our diets already high enough in magnesium?
4. Does magnesium deficiency cause heart trouble, is it the other way around, or is there a 3rd factor?

You don’t need to think of all of them before looking at the answer choices, but you should get in the habit of thinking of some. Any of them could be the basis for a correct answer.

___________

1. By showing that magnesium deficiency is common, this strengthens the argument.
2. This tells us one reason why magnesium is important, and could strengthen the argument.
3. Therefore older people would need more magnesium. Waiter, I’ll have some hard water please.
4. Does hard water have the same effect as magnesium supplements? The argument only advocates the former.
5. CORRECT. This shows that low magnesium is the result of heart disease (medications) and not the cause.

Recap: The question begins with “Researcher: Hard water contains more calcium and magnesium than”. It is a Weaken question. Learn how to master LSAT Weaken questions on the LSAT Logical Reasoning question types page.