Discussion
Which one of the following could be an accurate account
of all the kinds of material recycled at each recycling
center in Rivertown?
*This question is included in LG Sample 3: Difficult Games, question #8
| (A) | Center 1: newsprint, plastic, wood; Center 2: newsprint, wood; Center 3: glass, tin, wood |
| (B) | ... |
| (C) | ... |
| (D) | ... |
| (E) | ... |
| (F) | ... |
The solution is
Posted: 05/31/2011 11:29
What's the best way to solve this question? I can't see why B) is the answer.
Posted: 05/31/2011 15:52
This is a "complete and accurate" list question, so the deal here is you pick a RULE, find the answer choice that violates it, then strike that answer choice. Move on to the next RULE, and repeat the process. (Some people call these questions "Rule Checkers".) It may seem weird to start with rules instead of answer choices, but it's just plain ol' more efficient.
NOTE: this question has only three rules. But there are four wrong answer choices. So either one Rule will allow you to strike TWO answer choices, or one of the answer choices will violate some requirement laid out in the passage (such as "each recycling center recycles at least two but no more than three of these kinds of material").
Let's start with Rule 1:
And right off the bat, answer choice "A" violates Rule 1. Center 3 recycles W but not N.
Rule 2:
Choice "C" violates this Rule. Center 2 recycles tin, but Center 1 does not. Strike "C".
How about Rule 3? Rule 3 has two parts. What do you want to bet that one part is violated by each of our remaining wrong answer choices?
Rule 3a:
Choice "E" features two Centers that recycle P. Strike choice "E".
Rule 3b:
Choice "D" recycles glass and plastic. "D" is wrong.
And you're left with "B". Remember, these "complete and accurate list" questions are ALWAYS exercises in the process of elimination.
NOTE: this question has only three rules. But there are four wrong answer choices. So either one Rule will allow you to strike TWO answer choices, or one of the answer choices will violate some requirement laid out in the passage (such as "each recycling center recycles at least two but no more than three of these kinds of material").
Let's start with Rule 1:
And right off the bat, answer choice "A" violates Rule 1. Center 3 recycles W but not N.
Rule 2:
Choice "C" violates this Rule. Center 2 recycles tin, but Center 1 does not. Strike "C".
How about Rule 3? Rule 3 has two parts. What do you want to bet that one part is violated by each of our remaining wrong answer choices?
Rule 3a:
Choice "E" features two Centers that recycle P. Strike choice "E".
Rule 3b:
Choice "D" recycles glass and plastic. "D" is wrong.
And you're left with "B". Remember, these "complete and accurate list" questions are ALWAYS exercises in the process of elimination.
Posted: 09/07/2011 17:25
It says that any center that recycles wood must also recycle newsprint. No wood is recycled at centers 1 & 2 in option B
Posted: 09/07/2011 23:06
Whitney,
You're right, answer choice "B" has Newsprint but not Wood recycled in Centers 1 & 2.
So how can this answer choice be correct?
Let's look at Rule 1 again:
It says that if wood is recycled, then newsprint must also be.
In shorthand:
W → N
Your concern is that choice "B" has N, but no W.
But Rule 1 does NOT say:
N → W
You've committed the Converse Error--you've flipped the conditional around.
The LSAT writers use this mistake in creating trap answers all the time. The good news is that once you get familiar with conditionals, the Converse Error is easy to spot.
You're right, answer choice "B" has Newsprint but not Wood recycled in Centers 1 & 2.
So how can this answer choice be correct?
Let's look at Rule 1 again:
It says that if wood is recycled, then newsprint must also be.
In shorthand:
W → N
Your concern is that choice "B" has N, but no W.
But Rule 1 does NOT say:
N → W
You've committed the Converse Error--you've flipped the conditional around.
The LSAT writers use this mistake in creating trap answers all the time. The good news is that once you get familiar with conditionals, the Converse Error is easy to spot.
Posted: 09/08/2011 02:19
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