Forty-five percent of all blood donated in the United States is type 0

Question

Forty-five percent of all blood donated in the United States is type 0. Type 0 blood is essential for emergencies where there is no time for determining the blood type of victims because type 0 blood can be used for everyone. Type 0 blood is unique in that it is compatible with blood of all types: any recipient, regardless of blood type, can be given it. But precisely because of this special usefulness, type 0 blood is chronically in short supply.

If the statements in the passage above are true, which of the following must also be true?

(A) The special usefulness· of type 0 blood lies in the fact that it matches the blood type of most people.
(B) Supplies of type 0 blood are continuously so low that type 0 blood is unavailable for emergencies, where its usefulness would be greatest.
(C) Forty-five percent of the total population of the United States has type 0 blood, which makes type 0 the most common blood type.
(D) Any decision to give blood of any type other than 0 needs to be based on knowledge of the recipient's blood type.
(E) Type 0 blood is the only blood that cannot be typed as fast as needed in emergencies.

Sparta_750 · Answer

D

(A) The special usefulness of type 0 blood lies in the fact that it matches the blood type of most people

Incorrect: It doesn't matches the blood type of most people but is compatible with blood of all types. Even if one uses matches interchangeability with compatible, most vs all distinction still prevails.

(B) Supplies of type 0 blood are continuously so low that type 0 blood is unavailable for emergencies, where its usefulness would be greatest.

Incorrect: Supply low or not can not be inferred. What can be inferred is that supply cannot meet the demand as type 0 can be used irrespective of recipient's blood type.

(C) Forty-five percent of the total population of the United States has type 0 blood, which makes type 0 the most common blood type.

Incorrect: 45% of all blood donated is of type A.

(D) Any decision to give blood of any type other than 0 needs to be based on knowledge of the recipient's blood type.

Correct: It is mentioned that Type 0 blood can be given to any recipient regardless of his/her blood type. It is also mentioned that this application of type 0 is unique. Thus, decision to given other blood types can not be made in absence of knowledge of recipient's blood type

(E) Type 0 blood is the only blood that cannot be typed as fast as needed in emergencies.

Incorrect: Hilarious. Suggests that some sort of typing is involved in connection with blood.

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ankit1607 · Answer

Why not B?

it is explicitly mentioned that - "type 0 blood is chronically in short supply". So, already confirmed that supply is short foreseeing demand during emergencies.

Sparta_750 · Answer

ankit1607

The stem, in a subtle manner, implies that type 0 blood is short supply because it's demand is always more than its supply. Note the lines - "But precisely because of this special usefulness". The usefulness mentioned here is that it can be used for recipients with all type of blood types. So clearly, it's more about demand outstripping supply than supply being abysmally low.

Another reference (though not a strong one) can be that 45% of all blood donated is of Type 0. While it can still run a short supply, but then the emphasis would be more on shortage of over all blood supply and the stem wouldn't refer to it's usefulness as the cause of short supply.

Coming to (B)

(B) Supplies of type 0 blood are continuously so low that type 0 blood is unavailable for emergencies, where its usefulness would be greatest.

We do not know if Type 0 blood is 'so low'. We know that the demand is more than supply. Also, in the option Type 0 blood is mentioned to be unavailable for emergencies. If it is not used for emergencies, what is it being used for? Because isn't that the special usefulness that Type 0 can be used in emergencies without the need for determining blood type.

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honey1 · Answer

hey plz help me with this question 
if in option a we replace word match we compatible than option a can be our answer and how can option d be the answer as 
if person blood is o type then he do not need to know the blood type of recipient so how can this be possible if person blood type is not o then need to know the blood type of recipient
if o--->then no need to know
if not o---->then need to know

AndrewN · Answer

Hello,  honey1 . Choice (A) would still be on questionable ground if we replaced the word in question:

The problem lies in the use of  most , implying that not all people could be served type O blood. But that goes directly against the second line of the passage:  type O blood can be used for everyone . In short,  most  is not to be confused with  all .

Choice (D) is correct because of the third line of the passage:

If type O blood is  unique  in its universal compatibility, then other blood types must  not  be universally compatible. This simple understanding leads straight to (D):

There is no way to refute this statement, even without background knowledge of the other different basic blood types (A, B, or AB). Although in real life, type AB is known as the universal recipient, we can still appreciate how a type A blood could not be given to a person with type B blood, or vice-versa, and the person donating type AB blood had better have a matching recipient, since any of types A, B, or O in a recipient would be incompatible. (Remember, type O is the universal donor blood type, not the universal recipient.)

I hope that helps. If you have further questions, feel free to ask.

- Andrew

honey1 · Answer

Is the flaw in my reasoning was that if A then B do not necessarily means if not A then not B is wrong.I thought if not A then not B will necessarily be wrong i think that was the flaw in my reasoning it can also be right.
thank you so much

GMATGuruNY · Answer

I received a PM requesting that I comment. If an IF-THEN statement is true, then its CONTRAPOSITIVE is also true. I discuss this issue here: https://gmatclub.com/forum/for-a-trade- ... 45-20.html From the passage: Rephrased as an IF-THEN statement: If there is no time for determining the blood type, then type O is used. To get the contrapositive, we FLIP AND NEGATE: If type O is not used, then there must be sufficient time to determine the blood type . Option D paraphrases this contrapositive: Any decision to give blood of any type other than 0 needs to be based on knowledge of the recipient's blood type. In other words: If type O is not used, then there must be sufficient time to determine the blood type . D

honey1 · Answer

can you plz tell me whats the flaw in this reasoning AND IF THIS IS correct than option d is just the wrong negation.
if BLOOD TYPE is o--->then no need to have the knowledge of recipient blood type
if BLOOD TYPE is not o or any blood type other than o---->then need not to have the knowledge of recipient blood type
THANK YOU

GMATGuruNY · Answer

The red statement belongs not in the IF-portion but in the THEN-portion.
From the passage:
 Where there is no time for determining the blood type of victims...type 0 blood can be used. 
Rephrased as an IF-THEN statement:
 If there is no time for determining the blood type, then type O can be used.

Moreover, the conclusion in your post -- highlighted above in blue -- is illogical.
Consider the following case:
Amir enters the hospital for a medical procedure.
A blood test indicates that he has blood type O.
As a result, Amir is given a transfusion of blood type O during the procedure.
Clearly, the use of blood type of O does not indicate that there was no time or need to determine Amir's blood type.

VerbalBot · Answer

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Forty-five percent of all blood donated in the United States is type 0

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Forty-five percent of all blood donated in the United States is type 0

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