How many people in Town X read neither the World newspaper nor the Glo

Question

How many people in Town X read neither the World newspaper nor the Globe newspaper?

(1) Of the 2,500 people in Town X, 1,000 read no newspaper.
(2) Of the people in Town X, 700 read the Globe only and 600 read the World only.

DS54402.01

ScottTargetTestPrep · Accepted Answer

Statement One Alone:

Of the 2,500 people in Town X, 1,000 read no newspaper.

Since 1,000 people read no newspaper, we know at least 1,000 people read neither the World newspaper nor the Globe newspaper. However, we can’t determine the exact number of people who read neither one of these two newspapers. For example, say there is a third newspaper called the Earth newspaper and 500 people in the town read only this newspaper; then there are at least 1,500 people who read neither the World newspaper nor the Globe newspaper.

Statement one alone is not sufficient to answer the question.

Statement Two Alone:

Of the people in Town X, 700 read the Globe only and 600 read the World only.

This does not provide us with sufficient information to answer the question since we neither know the number of people who read both newspapers nor do we know the number of different newspapers in town.

Statement two alone is not sufficient to answer the question.

Statements One and Two Together:

Again, since we don’t know the number of different newspapers in town, we can’t answer the question.

Answer: E

saukrit · Answer

Well, aren't we supposed to know what all kind of newspapers are available in Town X for the people to read? We can not assume that there are just 2 newspapers available (the world and the globe)

Statement 1)  This would have been sufficient if we knew that people do not have a third choice. But we do not know. In case there are other choices apart from the world and the globe, then this is not sufficient. Strike off A and D

Statement 2)  We now have some good numbers, but we still do not know the number of people who read both. Moreover, we do not even know how many people are there. Strike off B

St 1 + St 2)  Still we do not have the number of people who read both the newspapers. If we knew that then the answer would have been simple to find = 2500 - (700 + 600 + People(who read both)). But with current data, we can't answer. Strike off C

Clearly, E is the answer

NX · Answer

Hi

We should not assume that there were only two newspapers available in TownX.

Let a,b and c represent the number of people who read only World, Globe and Other respectively. 
x represent the number of people who read both World and Globe.
y represent the number of people who read both Globe and Other.
z represent the number of people who read both World and Other.
m represents the number of people who read all the three newspapers. 
n represent the number of people who do not read any newspaper.

We have to find c+n.

(1) Total number of people in the town and number of people who read no newspaper are given.
n=1000
a+b+c+x+y+z+m+n = 2500
a+b+c+x+y+z+m = 1500 ->(1)
We know the value of n but we do not know the value of c. The given information is insufficient to find the value of c.

(2)Number of people who read only Globe and who read only World is given.
b=700 and a=600
We do not know the total number of people in TownX. The given information is insufficient to find the value of c+n.

(1) + (2) - Combining statements (1) and (2)
Even by substituting b=700 and a=600 in equation (1), the value of c cannot be determined.

Answer: E

WM88 · Answer

Why do we assume there are more than 2 newspapers?

mbeneduzi · Answer

In fact, we cannot assume that there are only two newspapers unless it is stated in the question. It is the same case for integers: we cannot assume that X can be only an integer unless it is stated in the question.

Studyhard101 · Answer

I still don't see why the answer is not A

sunny91 · Answer

ScottTargetTestPrep ,
Since 1,000 people read no newspaper, we know at most 1,000 people read neither the World newspaper nor the Globe newspaper.
Please let me know ow do you find that at least 1000 people read neither the World newspaper nor the Globe newspaper.
If you add a 3rd newspaper vendor,say X, then if 500 people read only X. Then we can assume that out of 1000 people, there are atleast 500 people wh do not read either the World newspaper or the Global newspaper. Please help me to understand where am I wrong in my understanding

ScottTargetTestPrep · Answer

The 1,000 people who read no newspapers is the minimum figure for the number of people who read neither the World nor the Globe. If there are only two newspapers, then there are exactly 1,000 people who read neither the World nor the Globe. You can increase this number by adding a third newspaper, say newspaper X; if there are people who read only newspaper X, then the number of people who read neither the World nor the Globe is 1,000 + the number of people who read only X.
Following your example, let's say there are 500 people who read only X. Notice that these 500 people are not included in the 1,000 people who read no newspapers, because they read a newspaper, which is X. In this example, if there are no other newspapers, the number of people who read neither the World nor the Globe is 1,000 + 500 = 1,500.

pankulsir · Answer

Since the gmat officially says, "nothing is to be assumed unless written", why is this question classified as hard?

ProfChaos · Answer

This Quant question turned into a CR question, real quick!

ChandlerBong · Answer

Hi Experts, Bunuel , KarishmaB , Can you please share your approach to this question? Also, why are we assuming the existence of a "third newspaper"? Thanks in advance.

KarishmaB · Answer

The trick here is that we are not given that Town X has only 2 newspapers. If it were a question on subjects in a college (say, 'how many students took neither History not Chemistry?') would we assume that there are no other subjects? No, we wouldn't. Similarly, we cannot assume here that there are only 2 newspapers in this town.

Our standard sets formula is this:
Total = World + Globe - Both + Neither

Neither -> the number of people who read neither World nor Globe.

Statement 1: 1000 people read no newspaper. This is NOT our Neither. We know that our Neither is 1000 or more but what it is exactly, we don't know. It is possible that there are 100 people who read a newspaper (so not a part of this 1000) but do not read World or Globe. Then our neither would become 1100 and so, Neither could take many different values.
The only thing thing this statement tells us is that Total = 2500

Statement 2: Gives us 'only Globe' and 'only World.' We don't know the value of Both. We can use another formula here
Total = Only Globe + Only World + Both + Neither
But we have 2 unknowns, Both and Neither

Using both statements, we don't know 'Both' and we don't know 'Neither.'
Answer (E)

ChandlerBong · Answer

Thanks for such a clear explanation, KarishmaB . Understood now!

bumpbot · Answer

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How many people in Town X read neither the World newspaper nor the Glo

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