The government will purchase and install new severe weather sirens for

Argument - Two types of sirens - old and new. If replacement parts are difficult to obtain --> new sirens will be fit.
(Things not to be questioned) - new sirens will enhance safety. Local company has gone out of business.
Conclusion - Public will be safer in the future.
How can the author make this conclusion? - For this the government has to install new sirens --> for this to be true the replacement parts have to be difficult to find.

(A) If public safety in the event of severe weather is enhanced next year, it will be because new sirens have been purchased.
- Negate this option: Safety will be enhanced not because new sirens have been purchased --> may be it is because of some XYZ reason. Ultimately safety is enhanced --> hence public will be safe in future --> thus this option does not even scratch the conclusion
- Wrong

(B) The newspaper was correct in claiming that public safety in the event of severe weather would be enhanced if new sirens were purchased.
- As noted there are some things which we cannot question in an argument. The given option is one of those things.
- Wrong

(C) The local company from which replacement parts for the old sirens were purchased last year was the only company in the area that sold them.
- Tricky but not correct. Even if there are other companies that sold them our major concern is whether the parts were difficult to obtain.
- This question does not shed light on the difficulty of obtaining the parts.
- Number of companies manufacturing the parts does not guarantee the easy availability of parts
- Close but wrong

(D) Replacement parts for the old sirens will be difficult to obtain if the government cannot obtain them from the company it purchased them from last year.
- Correct. If parts are difficult to obtain --> old sirens will be replaced by new sirens --> public will be safe
- Correct

(E) Because the local company from which replacement parts had been purchased went out of business, the only available parts are of such inferior quality that use of them would make the sirens less reliable.
- Again we need to focus on the ease of availability of replacement parts. Their quality is not our concern
- Wrong

If I understand correctly, The claim by the author cannot be questioned. However, the claim by any other entity can be questioned. Since B is a claim by the newspaper, we should be able to question that. Where am I wrong here ?

daagh GMATNinja

The question states, “The argument’s conclusion follows logically from its premises if which one of the following is assumed?” By asking about a situation in which the conclusion follows logically from its premises, the question allows us to take for granted that the premises are true.

With that in mind, here’s (B):


(B) is tempting. It seems like the newspaper would have to be correct in order for the author to conclude that “the public will be safer during severe weather in the future.” But that’s not actually ALL of the conclusion. The author concludes that “IF the newspaper is correct, the public will be safer during severe weather in the future.” So, the author allows for the possibility that the newspaper is NOT correct. In other words, (B) does not HAVE to be true because the author’s conclusion allows for the possibility that it is not true. This means that (B) is not a necessary assumption, and we can eliminate it.

I hope that helps!
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VeritasKarishma GMATNinja
for option C we can say - so what if it's the only company in THIS area, govt can order from some other area
then for option D also can't we say - so what if it's difficult to obtain parts, at least it is still possible
for option E it states that the only available parts are also of very low quality and hence they can't be used. so isn't option E most relevant?
please help.
thanks

Let’s consider the logic of the argument:

• The author concludes that, assuming the newspaper is correct, the public will be safer.
• He/she supports this because the newspaper claims that public safety will be enhanced “if new sirens were to be installed.”
• The government will purchase/install new sirens if replacement parts are difficult to obtain.
• And the company that sold replacement parts last year went out of business.

Underlying the argument is the author’s belief that new sirens will be installed. He/she think this because of the government’s criteria for purchasing new sirens: whether replacements are difficult to obtain. But we don’t actually know that. All we know is that the company that sold replacement parts last year has gone out of business. Does this mean that replacement parts will be difficult to obtain? Maybe. The author seems to think so, but he/she never explicitly states why.

With that in mind, the question asks that we find an assumption which, if drawn, ensures the conclusion follows logically from its premises.

Let’s take a look at (C):


(C) suggests that the replacement parts can’t be purchased locally, but they COULD still be purchased from another area. The problem is that we still don’t know whether parts purchased from other areas are difficult to obtain. It’s possible that the parts, even though they are not local, are NOT difficult to obtain. If that’s the case, the government will purchase replacement parts rather than new sirens, and the public will not necessarily be safer in the future. So, we can eliminate (C).


The passage has established that the government cannot obtain replacement parts from the same company as last year. That, in addition to what is given in (D), means that replacement parts will be difficult to obtain. If replacement parts are difficult to obtain, then the government will purchase/install new sirens. And if the newspaper is correct, new sirens mean the public will be safer. So, (D) logically leads to the conclusion drawn by the passage. Let’s keep (D).


The government’s criteria for deciding whether to replace parts or purchase new sirens is not whether the parts are of equal or greater quality to existing parts. Rather, the criteria is whether the parts are difficult to obtain. Even if the replacement parts are of inferior quality, the government could still purchase those inferior parts as long as they are not difficult to obtain. So, (E) does not necessarily ensure that new sirens will be purchased, and we can eliminate it.

(D) is the only answer choice remaining, and it is correct.

I hope that helps!
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GMATNinja, what makes A wrong? I am having a hard time negating it to convince myself that it is wrong.

GMATNinja what makes A wrong? I am having difficulties negating it to convince myself that it is not a suitable assumption. Can you please explain your thinking? Thanks!

quite a straight forward assumption question -
new parts ordered only if difficult to obtain> if not ordered from the particular company it is diff to obtain> no new sirens no increased safety.
D) must be assumed to justify conclusion.