The city’s center for disease control reports that the rabies epidemic

Hey, Can any expert help me to understand this? I am in general having a lot of difficulty with discrepancy questions.

Thanks

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AmanMatta, do you have a specific question? I can explain the whole the question, but if you have a specific answer that is troubling you I can focus on that.

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Since this is a Resolve the Paradox question type, we only expect to see premises. This argument tells us:

The CDC reported that the rabies epidemic “is more serious now than two years ago”. (Hmm, why’s that?)

25% was infected two years ago. Now, 50% are infected. (Well, that’s a big jump! Looks like it’s pretty serious.)

BUT, newspapers said they only counted up 32 cases two years ago, but only 18 cases were confirmed this year! (Dang, that’s odd! We’d expect the confirmed cases to go up, right? Well, I guess that’s the paradox I’m supposed to solve.)

Hm, let me think through some answer choices I might see about the newspaper report discrepancy:

The infected might have all died in the last year.
The newspapers might have discovered that their procedure for confirming cases was wildly overstated two years ago. (You know how news is! Sensationalism!)
The infected raccoons somehow gained immunity over time. (Yeah, this one is pushing it.)

Which one of the following, if true, most helps to resolve the apparent discrepancy between the two reports?


Well, we’re talking about rabies, but “wild animals OTHER than raccoons”? That’s a big NO. This is a clear diversion from the case at hand. Probably what Manhattan GMAT would label a No Tie type of wrong answer, since other animals don’t matter us!


Aha! Dang, we’re getting good at this anticipation stuff! Let’s make sure we can confirm that we’re right.


What? Why did we suddenly start talking about “distemper”? Hm, symptoms that “are virtually identical to those of rabies”….could it be that the confirmed cases were actually distemper cases and not true rabies cases? BUT this throws the whole argument under the bus.
A bigger issue with this answer choice is that “distemper” has the same symptoms as “rabies” so….we still have rabid racoons. And our newspaper report is still UNEXPLAINED.


This answer choice is tell us about the effect of the epidemic, but does nothing to explain our problematic newspaper report! This has No Tie to our stimulus.


“Neighbouring cities” also showed declining cases is great and all but serves us 0 information about OUR city and OUR news report. The argument doesn’t address neighbouring cities!

Hi nightblade354 Although I think B is be the best from all, are we still supposed to assume in some way that the population of raccoons has decreased because they were affected the most the year before last, I mean I dont quite get it how are we supposed to say that if a lot of raccoons were infected with rabies last year, then this year there may be a decrease in the overall raccoons and thus % is also less. I mean we just dont have total population or its dynamics, right?

We are trying to resolve a paradox of:

1. % of population infected went up
2. Actual number reported went down

In doing so, we are trying explain how both statements could be correct, yet lead to different conclusions. Your thought process is correct, but we have to remember what we are trying to solve for. We are not given population, but we are given % of infected for the time periods.

Totally agree. The thought that should immediately come to mind is that the denominator is smaller. That's the only way we will see a 50% increase in the number of infected racoons, but have a smaller numerator.

Hi CEdward, I'm not great with visualizing %/numbers within 2-minutes for Qs like these, if you dont mind can you explain the denominator and numerator scenario a bit more? so that I can apply the same in similar questions?

Sure thing.

Think about fractions. You have a numerator (X) and denominator (Y) such that X/Y

Now, there are two things you can do to the fraction, increase the size of it, or decrease its size. You can increase/decrease the size in three ways each:

Increase -
a) Increase the numerator (X) and keep the denominator (Y) constant
b) Decrease Y and keep X constant
c) Decrease Y and increase X

Decrease -
d) Decrease X and keep Y constant
e) Increase Y and keep X constant
f) Decrease X and increase Y

In this problem, the paradox is that the percentage of infected raccoons increased, yet strangely the total number of raccoons decreased. How can that be? Well, the answer is that the total number of raccoons (Y) decreased (they died in the year prior to last) and hence, the numerator X (18) represents a larger portion of the total (50%).

You should understand the distinction (and relationship) between percentages and numbers, particularly because the former can be misleading

e.g. A high percentage DOES NOT imply the involvement of a large absolute number (but it can);
Let's say the total number of students is 5 and 4 of them read so the percentage is 80%. The absolute number of individuals is very small and yet the percentage is high

e.g. A low percentage DOES NOT imply the involvement of a low absolute number (but it can)
Let's say the percentage of students who read is 80%. This can be 4/5, 400/500, 4000/5000, etc.