Self-study
Conclusion Wealth is not a good thing, for Support good things cause no harm at all, yet Support wealth is often harmful to people.
Method of Reasoning
This is a valid argument based on the contrapositive.
good thing → cause NO harm
wealth → does cause harm
Conclusion:
wealth → NOT a good thing
(Use the contrapositive of the first premise — if something DOES carm harm, then it’s not a good thing. Note that the “often” in the second premise shouldn’t be translated as a “some.” That’s because the point of stating that wealth is often harmful is to indicate that wealth is something that does cause harm — whether it happens “often” or more often than that isn’t what’s important. What’s important is that wealth does cause harm. That’s why it would be wrong and missing the point of the argument to diagram “often” or to think that it’s important to the reasoning.)
25.
Which one of the following █████████ ██ ████ ███████ ██ ███ ███████ ██ █████████ ██ ███ ████████ ██████
a
Alex loves to █████ ███ ██ ███ ██ ███ █████ ████ █████ ██ █████ ██ ███████ ████ ████ ██ ███ ██ ███ █████ █████
This is a valid argument based on the contrapositive.
chess club → NOT love to golf
Alex → loves to golf
Conclusion:
Alex → NOT in chess club
(Use the contrapositive of the first premise. If love to golf → NOT chess club.)
b
Isabella must be █ █████████ █████ ███ ██████ █ █████ ████ ███ ██████ ████ ██████ ████ ███ █████ ███████
This isn’t a valid arguement, so it can’t parallel the valid argument in the stimulus. (B) isn’t valid because even if all happy people smile a lot and hardly ever cry, that doesn’t imply that a baby that smiles a lot and hardly ever cries must be happy. (If you think it does, you’re confusing sufficient and necessary conditions.) Also, being “contented” is different from being “happy.”
c
Growth in industry ██ ███ █ ████ █████ ███ ███ █████ ████████ ███ ███████ █████ ████████ ███ █████████ █████ ██ ███████████
This isn’t a valid argument, so it can’t parallel the valid argument in the stimulus. The premises don’t tell us how we can prove that something “is not a good thing.” So there’s no way the conclusion, which asserts something is “not a good thing” can be proven true based on the premises. (The reasoning is cost/benefit analysis, not conditional. This is another way to eliminate (C).)
d
Sarah's dog is ███ █ ██████████ ███ ██ █████ ████ █████ ███ ████ ██████████ ████ ███████
This is not a valid argument, so it can’t parallel the valid argument in the stimulus. Even if most dachshunds hunt poorly, that leaves open the possibility that there are some dachshunds that hunt well, and Sarah’s dog might be one of the dachshunds that hunt well.
e
There is usually ████ ███████ ██ ████ ████ ██ ████ ██████ ██ ██ █ ████████ ███ █████ █████ ██ ███ █ ████████ ██ ██ ██████████ ████ █████ ██ ██ ██████ ████████
This isn’t a valid argument, so it can’t parallel the valid argument in the stimulus. Although the premises allow us to conclude that there is “usually more traffic at this time of day,” that doesn’t imply that having little traffic should be “surprising.” We could conclude that having little traffic isn’t the norm, but we don’t know that something outside the norm should be “surprising.”