gmatdog wrote:
The drought in the central part of the country is estimated to reduce this year's national corn harvest by more than one-third from its normal levels. Such a shortfall would subsequently increase meat and other food prices by about 17% in one year and 20% in two years. So, either we spend a small amount now to irrigate the largest affected corn fields and avert severe inflation later, or else fail to irrigate now and insure [ensure] inflation later.
The argument is valid only if
A. other American agricultural areas are also not expected to meet their anticipated corn yields this year
B. irrigation is the only way that the national corn yield can be significantly increased
C. the heat wave and drought will persist through the next two years
D. irrigation will insure [ensure] that corn harvests reach normal levels
E. it is politically feasible for government authorities to spend money irrigating fields at the present time
CLAIM: 1) We either have to irrigate the largest affected corn fields –or—
2) Fail to irrigate now and ensure inflation later
Basically, this argument is saying, irrigate OR ELSE! We need to find an answer that shows us that irrigation is the ONLY MEANS of averting inflation.
GOAL:Find an answer that proves that it’s irrigate or else suffer inflation.
THE OPTIONS:
A. other American agricultural areas are also not expected to meet their anticipated corn yields this year
Wrong: Shade of Gray. If other areas are also not expected to meet their anticipated yields, would that prove that we either have to irrigate or face inflation later? It points us in the right direction, but it doesn’t PROVE that we either need to irrigate or face inflation later. This is what we’d like to call a shade of gray answer.B. irrigation is the only way that the national corn yield can be significantly increased
YES! This answer proves that we either need to irrigate or face inflation later, because this answer tells that there is no other means.C. the heat wave and drought will persist through the next two years
Wrong: Shade of Gray. If the heat wave and drought will persist for through the next two years, would that prove that we either have to irrigate or face inflation later? No. This answer tells us that similar conditions will persist, but it doesn’t prove that we HAVE TO irrigate to stave off inflation.
D. irrigation will insure [ensure] that corn harvests reach normal levels
Wrong: Shade of Gray. Obviously, this adds support that irrigation works, but does this prove that we either that we either have to irrigate or face inflation later? This answer might seem tempting, but it only shows that irrigation can work, but NOT that irrigation is the ONLY way. There could be many other ways in addition to irrigation that could ensure that corn harvests reach normal levels. So saying that irrigation will ensure that corn levels reach normal levels does NOT actually prove that its irrigation or else.E. it is politically feasible for government authorities to spend money irrigating fields at the present time[/quote]
Wrong: Out of Focus. Does this prove that we either that we either have to irrigate or face inflation later? Even if there were funding available, helps only addresses the likelihood of feasibility, but that wouldn’t prove that we either have to irrigate or face inflation later. Correct Answer: B. It is the only option that proves that its irrigation or else face inflation.A side note: this is a pretty rare variation of an assumption question on the GMAT, known as a SUFFICIENT assumption question. We’re asked to find the assumption that’s sufficient for the argument to hold. GMAT assumption questions almost always ask us to find an answer taken for granted by the argument, also known as a NECESSARY assumption. SUFFICIENT Assumption questions ask us to find an assumption that essentially proves the argument, so they require a different framework to select the right answer than the typical GMAT style assumption question.
Necessary assumption questions are FAR more frequently found on the LSAT.
Also note, the context here would mean the word “insure” would have to be “ensure”.