There are far fewer kidneys available for transplants than there are

Question

There are far fewer kidneys available for transplants than there are patients who are waiting for a new kidney. As evidence of this, nearly 85,000 patients are currently on the waiting list for a kidney transplant, but last year only 16,000 kidney transplants took place.

Which of the following is an assumption required by the argument?

(A) The number of patients on the kidney waiting list has increased substantially since last year.

(B) The number of kidney transplants in the last year is greater than in any previous year.

(C) The number of kidney transplants that take place each year is not significantly different from the number of kidneys available over that time period.

(D) The process for preparing both donors and patients for a kidney transplant often requires several consultations with a doctor and a cumbersome amount of paperwork.

(E) The number of available kidneys has not increased since last year.

KarishmaB · Accepted Answer

Premises:

1. Last year, only 16,000 kidney transplants took place. 
2. This year, nearly 85000 patients are on the list.

Conclusion:
There are far fewer kidneys available than there are patients.

All we know is that there are many patients but last year, very few transplants took place. We are concluding that kidneys available are few and that is the reason that transplants are few (because we know that number of patients is definitely high). What is the assumption? The assumption is that had more kidneys been available, more transplants would have taken place. Note that from the "number of transplants" figure, we are concluding something about "number of kidneys available". What if the number of kidneys available is far more but transplants are fewer because of reasons such as a match doesn't happen, most kidneys available are not suitable for transplant etc. Hence (C) is our assumption.

Option (E) is not correct.
E) The number of available kidneys has not increased since last year.
Even if the number of available kidneys has increased this year, it is still possible that number of kidneys available is far less than the number of patients. We don't know how many kidneys were available last year and how many patients were there last year. We don't know how many kidneys are available this year. The point is that number of available kidneys and number of transplants may not be proportional.

KarishmaB · Answer

You have to be very careful in CR - notice what they are talking about in each sentence. Let's assume variables for clarity.

A - Kidneys available for transplant
B - People waiting on the list for transplant
C - Actual number of transplants that take place.

The argument says this:

A is much less than B.
As evidence, B is 85000 while C is only 16000.

Note that the evidence gives you the numbers of B and C. But we conclude that A is much less than B. How can we do that? The only conclusion from this evidence can be that C is much less than B. How do we conclude that A is much mess than B?

For that we need to assume that A is almost same as C. This is exactly what option (C) tells you. Hence, option (C) is the assumption.

cssk · Answer

Thanks for your reply. I initially picked E, which I negated and concluded that if " The number of available kidneys has increased since last year " then the difference between the number of available kidneys and number of people waiting for transplantation will be reduced. Thereby the conclusion of the argument would be hurt.

Even though the number of available kidneys increase, there is a possibility that even more number of people are awaiting transplantation this year. In this case, the argument still holds true.

If an answer choice has to be true, there should be no room for any reason to attack the argument pertaining to the information given in that answer choice.

Hope that helped you guys.

shiblee · Answer

I am still confused because

2013 , patients = 16,000

The number of transplants took place =16,000 !

But this year 2014, number of patients = 85,000

number of available kidneys = no information is given in the question

or the number of transplants will take place we do not know .

within one year period if the number of patients is increased significantly , then Can C be assumption of the argument ?

Posted from my mobile device

KarishmaB · Answer

The question does not intend to compare last year and this year figures. We know how many patients are waiting this year (85,000). But right now, we don't know how many transplants will happen so we take a clue from last year (16,000). So we conclude that number of kidneys available is far lower than patients. But 'number of kidneys' data is nowhere to be found in the argument. We are assuming that number of kidneys available is the only limiting factor for transplants. So (C) is our assumption.

Praveen_Seelam · Answer

Hi All, 
I'm really confused with answer choice C,
 if the number of kidney transplants that take place each year is not significantly different from the number of kidneys available over that time period; which means the number of kidney transplant that take place each year is almost close to the number of kidneys available over that time period, then where does the lag in kidneys come from ? 
argument does not talk anything about kidneys not matching or blood group not matching, so are we supposed to assume that ? how can choice C is an assumption required by argument ?

thanks

tyagigar · Answer

when when negate the assumption the conclusion should fall apart. Is this applicable in every case?
If yes let me try to negate C and see if in any case the conclusion holds:-

assumption:

The number of kidney transplants that take place each year is not significantly different from the number of kidneys available over that time period.

Negate the assumption:
The number of kidney transplants that take place each year is significantly different from the number of kidneys available over that time period.

when we say the number of kidney transplants that take place each year is significantly different from the kidneys available, can we not say transplant done --1000
kidney available- 3 .... the two numbers are significantly different ,, but in this case the the conclusion still remains intact

conclusion :
There are far fewer kidneys available than there are patients.

Please correct me if i am going wrong with my approach.

Thanks:
Gaurav

KarishmaB · Answer

If there are only 3 kidneys available, how can 1000 transplants be done? The number of transplants will obviously be less than or equal to the number of kidneys available.

test1cool · Answer

Thank you for your explanation, it is useful. While examining the issue, however, I used a similar thinking process but got to an alternative response. My question is, how can we accurately pick option C when it does not specificaly state wether the difference between the nr of transplants and kidneys available differs in a positive or negative manner. What I mean is, what if the number of kidneys available differs in that it is much lower than the number of transplants?

Option c does not necessarily indicate that the number of kidneys availalbe is greater than the number of transplants.

Option c does not necessarily indicate that the number of kidneys availalbe is greater than the number of transplants.

rak08 · Answer

I dont understand how is C correct  egmat   GMATNinja  @karshimaB

C negation would be : The number of kidney transplants that take place each year is  not  significantly different from the number of kidneys available over that time period.

So this means there is a gap between kidney available vs kidney transplants that took place
which doesn't break what the para says which is that kidney available < kidney transplant waiting.

egmat · Answer

Conclusion:  There are fewer kidneys  available  than patients waiting.
 Evidence:  85,000  patients on the waiting list, but only  16,000  transplants took place.

Now here's the  critical  question:  Does the number of transplants actually tell us anything about the number of kidneys available?

The argument uses " 16,000  transplants" as a  stand-in  for "number of kidneys available." It's basically saying: "See, only  16,000  transplants happened, so roughly  16,000  kidneys must have been available - way fewer than  85,000 ."

But this reasoning ONLY works if transplants ≈ available kidneys.  That's exactly what Choice C states.

You correctly negated C to: "The number of transplants  IS  significantly different from the number of kidneys available."

Imagine the negation is true. Transplants and available kidneys are very different. What if  80,000  kidneys were actually available, but only  16,000  transplants happened because of surgical capacity, matching problems, or paperwork delays?

In that case:
→ The conclusion ("fewer kidneys than patients")  collapses  - there would be nearly enough kidneys for everyone.
→ The evidence ( 16,000  transplants)  tells us nothing  about how many kidneys were available.

Answer: C

Choice C is the  bridge assumption  - it connects the evidence (transplant numbers) to the conclusion (kidney availability). Without it, citing transplant data as proof of a kidney shortage makes no sense.

There are far fewer kidneys available for transplants than there are

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There are far fewer kidneys available for transplants than there are

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