LSAT 123 | Section 2 | Logical Reasoning: Q13

LR Question 13 Explanation

QUESTION TEXT: Standard aluminum soft-drink cans do not vary in the amount…

QUESTION TYPE: Sufficient Assumption

CONCLUSION: Group M has twice as many cans as group L.

REASONING: Half of the aluminum in group M came from cans in group L. The cans in both groups are made almost entirely of aluminum.

ANALYSIS: This may already seem like a good argument. When that happens, you have to ask “how could this be wrong”.

Well, what if only 10% of aluminum in cans can be recycled? Then that would mean 100 cans in L would only allow 10 recycled cans to be made. That would mean group M would have only 20 cans, five times fewer than group L had.

If we assume that 100% of aluminum can be recycled, then this argument is correct.

___________

1. This answer is about what will happen to the aluminum in the future. But the argument is about where the aluminum came from in the past.
2. Quality is irrelevant. The argument is only about the number of cans, not how good they are.
    
   You might be assuming that some poor quality aluminum couldn’t be used, but that’s not what this answer says.
3. CORRECT. If this is true, then the argument is correct. The argument already said that all the cans in group L were turned into cans in group M. And we know that aluminum from L was half the material in M. So M would have to have twice as many cans as L.
4. It doesn’t matter where the aluminum in L came from. We care about where the aluminum in L went.
5. This is a very weak answer. It goes in the same direction as C, except C absolutely proves the argument. Whereas this answer might mean you could save 21% of the aluminum in cans, vs. 17% of some other metal.