Radio Stations with radio data system (RDS) technolodgy broadcast spec

well my guess was D ; but after 4 mins i drilled down to A...

actually the stimulus states that the reason why the no. of people recieving the program has not increased is that
the number of radios has not increased.To conclude this there must be assumption like on of the following :

-Before or during 1994 people didn't have radios which had RDS (coz they might initially be having radios that had RDS , in that case once the technology is there
those radios which were not used that much before 1994 would be used more by 1996 )

- Now like A says that though there is incease in the number of stations but the "covegare" is small hence those people with RDS radios who were not recieving any signal before still continue to recieve no signal and hence no increase.

At first I picked E, but now I understand why A is correct.

Based on the question we know RDS-reception requires 3 things:
1) Station must send RDS info with signal
2) Receiving radio must be able to decode RDS information

Also we know:
the number of stations grew from 250 to 600
the number of receivers stayed the same

The conclusion is "..the number of verdlanders receiving the special program information probably did not increase significantly. "

In this problem we must support this conclusion (in my opinion a poor one) with a key assumption.

Choice A is basically saying the additional RDS stations are in the same broadcast area as the previous RDS stations.

I have a diagram to illustrate a situation without assumption A.



As you can see in the drawing, an additional station in a different area of Verdland could increase the number of people receiving the RDS information.

For anyone wondering why the broadcast area for the blue station is not a circle, the broadcast tower is in a deep valley.

My guess is the official guide would call C outside the argument.

C is an assumption that is not key to the argument. If we assume the opposite:

Equipping a radio station with RDS technology does decrease the station's listening area.

The conclusion still stands "..the number of verdlanders receiving the special program information probably did not increase significantly."

In fact if the opposite of C was true, this would give support to the conclusion "....number of verdlanders did not increase significantly." (If adding RDS capability decreased listening area then the number of verdlanders who have access to RDS could actually decrease.)

When the conclusion is stated "did not" you end up with A or B outcome.

In this case we have:
A: the number receiving RDS did not increase significantly
or
B: the number receiving RDS did increase significantly

A would include:
*a significant decrease
*a minor increase
*a constant level
*a minor decrease

As I stated in my other post this is a very weak conclusion. Using "...probably not increase significantly" reminds me of a politician.

Such as: "Good news, the growth in the unemployment rate was not as large as expected."

I believe D is straight no ! In 1996 Verlanders who did not own radios equipped to receive RDS
- this means the group it is considering is wrong / unrepresentative. It is imperative to have a correct receiver. That is the assumption for the things to work.

Premise : Radio stations with radio data system (RDS) technology broadcast special program information that only radios with an RDS feature can receive.

A is answer !

There is a distinction between:
Few - Very few
A few - Some
Few of my friends will go to the dance. (means very few or almost none of them will go)
A few of my friends will go to the dance. (means some of my friends will go)

So I would consider 'Few if any' to mean 1 or 2 if any at all... That number may not have enough impact to make a difference.

The question asks for an assumption. (i.e. what is necessarily true to make the conclusion true?)
The gist of the argument is that since no. of radios is about the same, number of people receiving the RDS programming is also the same.

Option D - In 1996 Verlanders who did not own radios equipped to receive RDS could not receive any programming from the RDS radio stations that began broadcasting in Verdland after 1994.

- Even if people without RDS equipped radios could access RDS programming (say on neighbor's RDS radio) in 1996, they could have done the same in 1994 as well. They could have received RDS programs from existing radio stations (using neighbors radio). The number of people receiving the programming then may not have changed. So the argument could still hold even if option (D) is false. It is not necessary for it to be true for the argument to be true. Then option (D) is not an assumption.

(Recall Assumption Negation Technique (ANT). Assumption is something which needs to be true for the conclusion to be true. That is why it is called an assumption. If an option is negated and the conclusion could still hold, it is not an assumption)

On the other hand, if we negate option (A) and say that some RDS radio stations started broadcasting in areas which were not previously reached by RDS but where people owned RDS equipped radios, then the number of people receiving RDS increases in 1996 and the conclusion does not hold. Hence option (A) is the assumption.

I am sorry maddy2u but I am not very sure what you mean. If the radios are not equipped with RDS, how could they get RDS programming? Do you mean using someone else's radio? Then my explanation above may help. If you mean that they could kind of install a software that supports reception of RDS on their radios (just taking a shot here!) or something, they could have done the same in 1994. How do you prove that the number of people receiving RDS programming has changed from 1994 to 1996? Only if you do that can you break the argument.

Assumption question: Find the conclusion. Find out which answer option is essential for the condition to be true.

Premises:
-Only radios with RDS feature can receive programs of Radio stations with RDS technology
-Between 1994 and 1996, the number of RDS radio stations in Verdland increased from 250 to 600.
- the number of RDS-equipped radios in Verdland was about the same in 1996 as in 1994


Conclusion:the number of Verlanders receiving the special program information probably did not increase significantly.

Even though new RDS radio stations have been set up, since the number of radios with RDS feature is same in 1996 as in 1994, the author is concluding that the same number of people are receiving RDS programs.

a. Few if any of the RDS radio stations that began broadcasting in Verdland after 1994 broadcast to people with RDS-equipped radios living in areas not previously reached by RDS stations.

What if the new RDS radio stations were set in areas which did not receive RDS programs before.. (say, if that particular frequency was not available in remote areas but when new radio stations were set, these areas starting receiving RDS prgrams.) There might be people in these areas who already had RDS equipped radio. These people would have started receiving RDS programs (e.g. Initially FM had limited reach and though many radios had FM capability, they could not receive it. After FM became common, even though people didn't buy new radios, more people started receiving FM)
So for his conclusion to be true, the author is assuming that RDS radio stations that began after 1994 did not broadcast to people who were unreachable previously. Hence answer A.

(C). Equipping a radio station with RDS technology does not decrease the station's listening area.
This is not an assumption the author is making. The conclusion says ' the number of Verlanders receiving the special program information probably did not increase significantly' based on the fact that the number of RDS equipped radios is the same.
To understand this, try to negate the assumption: Equipping a radio station with RDS technology decreases the station's listening area. Can our conclusion "the number of Verlanders receiving the special program information probably did not increase significantly." still hold true? Most certainly. In fact, it is more likely that our conclusion is true. Since our conclusion can hold even if the supposed assumption is negated, it is not an assumption at all.

Gist of what D says: No RDS enabled radio meant no RDS program reception from later radio stations.
Conclusion of the argument: Number of people receiving RDS program did not increase significantly in 1996.

We have to consider whether D is an assumption. An assumption is a necessary missing premise. If the assumption is not true, the conclusion cannot be true. Let's negate the assumption. Then we will whether the conclusion can still hold.

Negated D: Even without RDS enabled radios, people could receive RDS programs from later radio stations.
Can the conclusion still hold true? Sure. If people can receive RDS programs without an RDS radio (e.g. at friends/neighbors etc) from later stations, these people could have received RDS programs in the same way before 1996 too. So number of people receiving RDS programs could have stayed the same. Since the conclusion can still hold even if D is negated, D is not an assumption.

I was slow on this (4 min), but the answer should be A.

1) ID question type: Find the Assumption.
2) Deconstruct the Argument:

- RDS is only received by special RDS radios.
- '94 to '96: RDS stations increase from 250 to 600.
- # of RDS radios in the the country same in '96 as '94.
- Conclusion: # of People in country who receive RDS signals did not increase.

Logic gaps in the argument: Just because someone owns an RDS radio doesn't mean he can receive the signal (maybe he's not in range of a station?). If he was out of range of a station in 1994 with an RDS radio living in the outback wilderness, but all of a sudden in 1996 a new station pops up on a mountain top nearby, then he would be able to listen. So we need to find something that assures us that all RDS owners in '94 had reception and can listen to RDS stations.

3) Remind yourself of the goal: Find the Assumption Question type.

4) Wrong from wrong to right (process of elimination):

a. Few if any of the RDS radio stations that began broadcasting in Verdland after 1994 broadcast to people with RDS-equipped radios living in areas not previously reached by RDS stations.

- Here I'm thinking that this one could be good. It's saying that few NEW stations built after 1994 were built in NEW areas...so that means that RDS coverage remains about the same in the country. It answers our logic gap above. I'll leave this one and analyze my other choices.

b. In 1996 most Verdlanders who lived within the listening area of an RDS station already had a radio equipped to receive RDS.

- This isn't really providing us with any important information to bridge the logic gap. In 1996, people in range can listen. Whoopty-do. Eliminate B.

c. Equipping a radio station with RDS technology does not decrease the station's listening area.

- So range doesn't change when a station has RDS technology. This doesn't matter as we are trying to bullet-proof our argument against whether or not the NEW stations reached NEW listeners. It doesn't deal with the new stations being built. Eliminate C.

d. In 1996 Verlanders who did not own radios equipped to receive RDS could not receive any programming from the RDS radio stations that began broadcasting in Verdland after 1994.

- Is this really telling us anything new? We already know that people without special RDS radios can't receive RDS signals. Eliminate D.

e. The RDS radio stations in Verdland in 1996 did not all offer the same type of programming.
- Irrelevant. Who cares what they broadcast? It has nothing to do with reaching new listeners. Eliminate E.

No, that wouldn't be an assumption either.

Note that the point is not how far the RDS stations can transmit. Even if they transmit everywhere now, it is worthless if people do not have RDS equipped radios. Since no of people with RDS equipped radios has stayed the same, the author is saying that number of people receiving RDS programming is the same as before even if RDS stations cover more area now. So even if RDS tech increases the listening area, still number of people receiving the RDS programming could be the same since number of RDS equipped radios is the same. Hence the modified statement is not an assumption.
The assumption is that the new stations are not broadcasting in areas where RDS programming was not available before but people still had RDS equipped radios. If this were not true, people with RDS equipped radios would have started receiving RDS programming and the author's conclusion would be violated.

This argument has a parallel in the real world. In 1980s and early 1990s, most cities in India did not have FM channels but most radios came with FM because it became a standard feature - so that people living in cities with FM channels can access them.
Then in 1990s, many new FM channels came up in many cities. Did many more people buy FM equipped radios? Perhaps no. But did many *new* people start receiving FM channels? Sure. They already had FM equipped radios and FM broadcasting started in their cities so they started receiving it.

So when we say that since many new radios with RDS were not bought so people getting RDS did not increase, we are assuming that RDS programming did not start in areas which did not have it before but where people had RDS equipped radios.

"Special programming" is "RDS programming" i.e. programs from RDS stations. This is the same as "any programming from the RDS radio stations"

The question asks for an assumption. (i.e. what is necessarily true to make the conclusion true?) If (D) is false but the argument COULD still hold, then (D) is not an assumption. You have to look for ways in which the argument CAN HOLD. Not the ways in which the argument can be made false.

The gist of the argument is that since no. of radios is about the same, number of people receiving the RDS programming is also the same.

Option D - In 1996 Verlanders who did not own radios equipped to receive RDS could not receive any programming from the RDS radio stations that began broadcasting in Verdland after 1994.

- Even if people without RDS equipped radios could access RDS programming (say on neighbor's RDS radio) in 1996, they could have done the same in 1994 as well. They could have received RDS programs from existing radio stations (using neighbors radio). The number of people receiving the programming then MAY NOT have changed. So the argument COULD still hold even if option (D) is false. It is not necessary for it to be true for the argument to be true. Then option (D) is not an assumption.

Radio stations with radio data system (RDS) technology broadcast special program information that only radios with an RDS feature can receive. Between 1994 and 1996, the number of RDS radio stations in Verdland increased from 250 to 600. However, since the number of RDS-equipped radios in Verdland was about the same in 1996 as in 1994, the number of Verlanders receiving the special program information probably did not increase significantly.

Premise 1 : The number of RDS station increased from 250 (1994) to 600 (1996).
Premise 2: The number of RDS equipped radios (receiver) is still the same.
Conclusion : The number of people receiving the special (RDS) program did not increase significantly

Which of the following is an assumption on which the argument depends?

Argument structure:
Stations have increased -> but the number of people receiving the signal didn't increase.
What connects between Stations and people -> Coverage of the stations
So the coverage remains the same

A. few if any of the RDS radio stations that began broadcasting in Verdland after 1994 broadcast to people with RDS-equipped radios living in areas not previously reached by RDS stations.

The option actually says the "few" RDS stations were broadcasting to people after 1994 previously not reached by RDS statitions.
which implies that
Even though the number of the stations have increased significantly, but the coverage area remains the same
This is exactly same as that of argument structure analysis - Correct

B. In 1996 most Verdlanders who lived within the listening area of an RDS station already had a radio equipped to receive RDS.
We are comparing number of people receiving programs in 1996 and in 1994. This option talks about number of people owning radios in 1996 -> this options doesn't add any value to support the conclusion.

C. Equipping a radio station with RDS technology does not decrease the station's listening area.
This option talks about the "coverage" .
But this option also says that RDS doesn't increase the coverage area. But not only we are enabling RDS , we are also increasing the number of stations and increasing the number of stations is the premise of the argument. This option doesn't talk about the effect of the increasing number of the stations to the coverage of the people receiving the special programs.

D. In 1996 Verlanders who did not own radios equipped to receive RDS could not receive any programming from the RDS radio stations that began broadcasting in Verdland after 1994.
We are not talking about the people who are not receiving the RDS programs.

E. The RDS radio stations in Verdland in 1996 did not all offer the same type of programming.
Type of programming is out of scope

It means there was no "significant increase". If there was an increase, it was what you would expect in the normal course of things.

For example, the number of people watching channel A varies from 10 million to 10.5 million from time to time. Last Feb, data showed that 10.3 million people were regulars. A new set of programs were introduced in March. Till July, there was no significant increase. It mean that in July the numbers might have been 10.4 or 10.5 but nothing that we could say happened because of the new set of programs. It implies it was not out of the ordinary and that the programs did not have any/much effect.

Question is about assumption not inference.

When you negate this statement, it will shatter the conclusion. Hence, it is the correct answer.

Dear zoezhuyan
I'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

VeritasPrepKarishma , mikemcgarry

Option D clearly means that we are negating the premise which i think isn't permissible in GMAT. Is my reasoning accurate?