zoezhuyan wrote:
Dear experts,
I read lots of posts about option D for this case, but my confusion has not sorted out.
First, my confusion is the conclusion that the number of Verdlanders receiving the special program information probably did not increase significantly. I am not sure whether only I have this problem as below.
my doubt is the number of people receiving. The argument does state radio with an RDS feature can receive from those radio station with RDS , but does not state how people receive. for example, if 4 people are round the a radio with RDS , then 4 people can receive, if 400 people are round the same radio, then 400 people receive , right?
therefore, I think it is a big gap between the number of people receiving and the radio with RDS,
I did not negate D, (I am so poor at negating), when I read D, I get that people who have no RDS radio can not receive, so it eliminate my concern above. in other words , those who have no RDS radio won't get the access to special information through other methods, such as go to their friend who have RDS radios.
that's why I picked up D.
Review A, the core is radio station cannot early reach by RDS station, I think that it destroy the premise "radio with RDS is the only way to receive the special program information." whenever we meet CR, we accept the premises from the prompts, that's why I cross off A.
this question does confused me a lot. although I read lots of posts.
genuinely want your clarification.
thanks in advance, thanks million.
have a nice day
>_~
Dear
zoezhuyanI'm happy to respond.
My friend, you are confused about a few things in this question. First of all, I want to teach you a pair of technical logical words, to highlight one of your misunderstandings. These are the words "
necessary" and "
sufficient." One way to say it is as follows:
"
A is necessary for B." Here we know that if A doesn't happen, then B would not happen. If A doesn't happen, then it may or may not be true that B can happen.
For example, A might be "
car has gasoline" and B might be "
car is able to transport someone." It's absolutely true that if a car does not have any gas, it will not go anywhere. If the car has gas, it may be operational, or there many be any one of a host of other automotive difficulties that prevent it from going anywhere.
The word "
sufficient" summaries the opposite relationship.
"
A is sufficient for B." This means that if A happens, we know that B must be true; in other words, A is a guarantee for B. If A doesn't happen, then B may or may not be true. For example, here, A could "
car is able to transport someone" and B would be "
car has gasoline." If I drive the car from one place to the next, it is guaranteed that at least during the time I was driving, the car had gas. On the other hand, if I can't even turn the car on, it may be out of gas, or it may have another problem.
Overall, we can that "having gas" is
necessary but not sufficient for a car to be able to travel.
This prompt says that: "
Radio stations with radio data system (RDS) technology broadcast special program information that only radios with an RDS feature can receive." Much in the same way, having a radio with RDS technology is necessary but not sufficient for receiving this "
special program information." If my radio does NOT have RDS technology, then there's no way that I will receive that information. If my radio DOES have RDS technology, then that's helpful, but not a guarantee that I will receive the information. The radio may be not plugged in, or out of batteries, receiving poor reception, or be out of range, or the information might be broadcast in a language that I don't understand. Any of these scenarios, and many more, would result in cases in which my radio did have the RDS technology and still did not receive the information. All of this is consistent with the statement in the prompt. The mistake which caused you to cross off (A) was reading this "
necessary" statement as a "
sufficient" statement.
Your point about many people listening to a single radio is interesting. There aren't many real world scenarios, at least in the more developed countries, in which a large number of people regularly listen to a single radio. Also, typically, such places would be constructed specifically for that purpose: it would be quite unusual if a place were created that could accommodate 400 listeners, but at first, only four listeners were using it. No one constructs a big space if it looks as if only a handful of people are likely to use it.
Choice (D) is particularly interesting, because it is absolutely something that must be true, based on the statements in the prompt. If the prompt question had been, "
If the statements above are true, which of the following also must be true," then (D) would be the correct answer. It's the correct answer for the wrong question. It doesn't answer the question that actually was asked: "
Which of the following is an assumption on which the argument depends?" We can't really use negating to eliminate (D), because it has to be true given that the prompt statements are true. It's something true that must be true, based on the prompt, but it is not an assumption because it doesn't help link the premises to the conclusion.
Does all this make sense?
Mike
_________________
Mike McGarry
Magoosh Test PrepEducation is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)