Self-study
Altogether, the students in Ms. ███████████ ██████ ██████████ ██████ █████ █████████ ████ ████████ ████ ████ ███ ███ ████████ ██ ███ ██ ███ ████████ █████ ████████ ██████████ ███ ██████ ███████ ███ █████████ ███ ████ ████████ ████ ███ ██ ███ ███████████ ██████
Method of Reasoning
The argument starts with a comparison between sets of people (among all the classes at the school, the one that collected the most cans was Tarnowski’s). It then moves to a conclusion that compares individual members of those sets (among all the students at the school, the one that collected the most cans was in Tarnowski’s class).
Identify and Describe Flaw
This is a cookie-cutter whole-to-part flaw. The only support is about whole sets (classes), while the conclusion is about the individual members of those sets (students). But the performance of a class as a whole doesn’t tell us about the performance of any specific student, so we can’t infer that the student who collected the most cans is in Tarnowski’s class. It’s possible that a student in another class collected the most cans, while the rest of her classmates collected very few.
5.
Which one of the following █████████ ████████ ██████ █████████ ████ ██ ████ ████████ ██ ████ ██ ███ ████████ ██████
a
Altogether, more trees ████ ███████ ██ ███ ████████ ██ ███ ███████ █████ ████ ████ ███████ ██ █████ ██ ███ ███████ █████ ███ ███ █████████ █████ █████████ ██████████ ███ ███████ ████████ ███████ ████ █████ ████ ███ █████████ ████████ ████████
No flaw. If Kelly’s class planted more than Jackson’s + Liang’s combined, then it must be true that Kelly’s class planted more than Jackson’s (and also planted more than Liang’s).
b
More than half ██ ██████ ██████████ ████████ ████████ ████ ██ ███ ████ ███ ████ ████ ████ ██ ███ ████████ ████████ ████ ██ ███ ██████ ██████████ █████ ███████ ██ ██████ ██████████ ██████ ██████ █████ ██ ███ ████ ██ █████ ██ ███ ██████
Wrong flaw. This looks at two subsets (band members and choir members) and invalidly concludes that together, they make up the entirety of a larger set (all students at Milton Elementary). The stimulus, meanwhile, looks at several sets, makes a comparison between them, and then shifts to a conclusion that compares the individual members of those sets.
c
Mr. Rowe's Milton ██████████ ██████ █████ ██████ ████ █████ ██ ███████ █████ ████ ████ ███ ██████ █████ ██████ ██ ███████ █ ███████ ██████████ ███ ██████ ██ █████ ████ ████ ██ ███ ██████ █████ ███ ███████ ████ ███ ██████ ██ ██████ ███████ ████ ██ ███ ██████ ██████
Wrong flaw. This compares a certain characteristic (money raised) for two different sets (Rowe’s and Hunt’s classes) and then shifts to a conclusion that compares a different characteristic (tickets sold) for the same two sets. The stimulus, meanwhile, compares a certain characteristic (number of cans) across several sets and then shifts to a conclusion that compares the same characteristic (number of cans) but for individual members of those sets.
d
The total number ██ ███████ ██ ███ ██████ ████ ████ ██ ███ ████████ ██ ███ █████████ ██████ ██████████ ██████ █████ ███ ███████ ████ ███ ██████ ████ ██ ██████ ████████ ████ ███ █████ ██████ ██████████ ███ ██████ ███████ ███ ████ ███ ████ ███████ ██ ███ ██████ ████ ███ █ ███████ ██ ███ █████████ ██████
The argument starts with a comparison between sets of people (among all the classes at the school, the one that sold the most tickets was Ramirez’s). It then moves to a conclusion that compares individual members of those sets (among all the students at the school, the one that sold the most tickets was in Ramirez’s class). This commits the same whole-to-part flaw because the performance of a class as a whole doesn’t tell us about the performance of any specific student.
e
Ms. Ventura's Milton ██████████ ██████ █████ █████████ ████ ██████████ ████ ███ ███ ██ ███ ████████ █████ ████████ █████ ███ █████████ █████ ███ █████ ████████ ████ ███ █████ ██████ ██████ ███ ████████ █████████ ████ ███████████ ██ ████████ ████ ███ ███ ████████ ██ ███ █████ ██████ ██████
No flaw. This says that the smallest class in the school built the most birdhouses of any class. So it must be true that the average number of birdhouses per student is highest for that class (even if we don’t know how many birdhouses any specific student actually built).