标题: One question about CR Bible_looking for ur help [打印本页] 作者: rubymm 时间: 2015-1-11 14:34 标题: One question about CR Bible_looking for ur help Q: If Ameer is correct, either the midterm is cancelled or the final is cancelled. But the professor said in class last week that she is considering cancelling both tests and instead having strudents submit a term paper. Because the professor has final authority over the class schedule and composition. Ameer is probably incorrect.
Is this argument strong or weak? Please explain why?
Explanation from Bible: The argument is weak. Ameer has asserted that at least one of the two tests will be cancelled, and the professor is apparently considering cancellling both. No evidence presented to contradict Ameer's assertion, so there is no reason to conclude that Ameer is incorect.
My question:
1. Does 'either or' mean 'at least one of them'? I though it should be either midterm or final term, only one of them.
2. There is no contradict between 'either or' and 'both'?
thanks for answeing my quesiton.
作者: cherylyvox 时间: 2016-5-9 15:19
Hi, I had the same question and looked up some references. Here is my understanding. Hope it can help!
1. When A and B are not mutually exclusive, simply speaking "either or" means "at least one of them".
2. And under such circumstance, "either or" includes "both".
You can refer to some notes via this link http://blog.powerscore.com/lsat/bid/268836/When-does-either-or-mean-both-on-the-LSAT
However, in this argument, there is a more obvious mistake - using the word "probably". In PowerScore Forum, their staff explained the question as below (https://forum.powerscore.com/lsat/viewtopic.php?f=13&t=6932):
"In that one, Ameer thinks that one of those two tests is going to be cancelled. The teacher is considering cancelling both.
So would this prove Ameer wrong? Not really...as you alluded to, 'considering' tells us that the decision hasn't even been made. The professor controls the schedule, but it's not clear that the professor will do anything that contradicts Ameer's prediction. As such, we cannot conclude that Ameer is probably incorrect, so this is a weak argument. "
In short, the staff states that just a consideration (not an action) is not sound enough evidence to prove Ameer is "probably" incorrect.
In addition, if we have to look into this argument as a probability question, using "might be incorrect" is better than "is probably incorrect" (https://forum.powerscore.com/lsat/viewtopic.php?f=13&t=6093).
thanks for answeing my quesiton.