- PowerScore Staff
- Posts: 8916
- Joined: Feb 02, 2011
- Sat Jan 21, 2012 12:00 am
#60932
Complete Question Explanation
Must Be True—Formal Logic. The correct answer choice is (B)
This question clearly demonstrates the importance of understanding the correct flow of information between the stimulus and the answer choices. On a Must Be True question, like this one, all of the information in the stimulus is presumed true and used to prove one of the answer choices. Any answer choice or prephrased solution which cannot be proven solely by evidence from the stimulus must be incorrect, no matter how well it seems to fit.
The language in the stimulus – “each,” “at least some,” “some…are not” – indicates that this is a Formal Logic question. As with most Formal Logic questions, consider diagramming the stimulus and examining the resultant inferences, as this is often the key to quickly locating the correct answer. The first sentence can be diagrammed as:
Answer choice (A): Does answer choice (A) have to be true based upon the stimulus? No. The inference in the stimulus is that some people who received a community recognition certificate are not active in the town’s artistic community, but this does not imply that some people who received a community recognition certificate are active in the town’s artistic community. This is a common incorrect answer choice when dealing with “some” statements.
Answer choice (B): This is the correct answer choice. To many test takers, this answer seems almost too obvious to be correct. The stimulus states that everyone at the spring cleanup received a certificate and that some people at the spring cleanup are not active in the artistic circles, then it is evident that some people who received certificates are not active in the town’s artistic circles. Remember, though, that this is a Must Be True question – the answer is supposed to be evident. This is the correct answer, even though it contributes nothing to test takers’ understanding of the stimulus.
Answer choice (C): The stimulus does not infer that only spring cleanup participants received community recognition certificates. Perhaps the arts fair participants received certificates, as well. Furthermore, it is possible that some people participated in both events (even though they were at the same time, it is possible that some people could have left one event early to attend the other).
Answer choice (D): This answer choice can be diagrammed as “CRC
SC,” which is a Mistaken Reversal of the first sentence. Remember the difference between “Every A is a B” and “Only an A is a B” – specifying that all spring cleanup participants received certificates (the first sentence) is not equivalent to proving that they were the only ones who received such certificates (answer choice (D)).
Answer choice (E): Answer choice (E) is simply beyond the scope of the stimulus. It is entirely possible that every member of this community, including those who are active in the town’s artistic circles, is concerned with the town’s environment. It is equally possibly that everyone in town, including those who participated in the spring cleanup, is only concerned with collecting community recognition certificates.
Must Be True—Formal Logic. The correct answer choice is (B)
This question clearly demonstrates the importance of understanding the correct flow of information between the stimulus and the answer choices. On a Must Be True question, like this one, all of the information in the stimulus is presumed true and used to prove one of the answer choices. Any answer choice or prephrased solution which cannot be proven solely by evidence from the stimulus must be incorrect, no matter how well it seems to fit.
The language in the stimulus – “each,” “at least some,” “some…are not” – indicates that this is a Formal Logic question. As with most Formal Logic questions, consider diagramming the stimulus and examining the resultant inferences, as this is often the key to quickly locating the correct answer. The first sentence can be diagrammed as:
- SC = participated in the town’s annual spring cleanup
CRC = received a community recognition certificate
SC CRC
- TAC = active in the town’s artistic circles
SC 
TAC
- TAC SC CRC, therefore: CRC TAC
Answer choice (A): Does answer choice (A) have to be true based upon the stimulus? No. The inference in the stimulus is that some people who received a community recognition certificate are not active in the town’s artistic community, but this does not imply that some people who received a community recognition certificate are active in the town’s artistic community. This is a common incorrect answer choice when dealing with “some” statements.
Answer choice (B): This is the correct answer choice. To many test takers, this answer seems almost too obvious to be correct. The stimulus states that everyone at the spring cleanup received a certificate and that some people at the spring cleanup are not active in the artistic circles, then it is evident that some people who received certificates are not active in the town’s artistic circles. Remember, though, that this is a Must Be True question – the answer is supposed to be evident. This is the correct answer, even though it contributes nothing to test takers’ understanding of the stimulus.
Answer choice (C): The stimulus does not infer that only spring cleanup participants received community recognition certificates. Perhaps the arts fair participants received certificates, as well. Furthermore, it is possible that some people participated in both events (even though they were at the same time, it is possible that some people could have left one event early to attend the other).
Answer choice (D): This answer choice can be diagrammed as “CRC
SC,” which is a Mistaken Reversal of the first sentence. Remember the difference between “Every A is a B” and “Only an A is a B” – specifying that all spring cleanup participants received certificates (the first sentence) is not equivalent to proving that they were the only ones who received such certificates (answer choice (D)). Answer choice (E): Answer choice (E) is simply beyond the scope of the stimulus. It is entirely possible that every member of this community, including those who are active in the town’s artistic circles, is concerned with the town’s environment. It is equally possibly that everyone in town, including those who participated in the spring cleanup, is only concerned with collecting community recognition certificates.