A new machine for harvesting corn will allow rows to be planted only

What you are saying is somewhat valid. Notice, however, that if a farmer goes from planting corn 30 inches apart to planting corn 15 inches apart, then logically, it has become possible to plant twice as many plants as were planted 30 inches apart. So, the information provides by (D) logically follows from what the passage says.

Furthermore, there is an even clearer reason why (D) does not logically complete the passage.

The correct answer must support this conclusion:

the new machine will allow corn growers to double their profits per acre because

Now, notice that the passage says the following:

Corn planted this closely will produce lower yields per plant.

What does that information mean to us? I means that doubling the number of plants will not result in a doubling of profits, because the yield per plant will decrease. In other words, doubling the number of plants will not take the yield from x to 2x but from x to <2x.

So, what (D) says, "the number of plants grown per acre will almost double," cannot explain why a doubling of profits will occur.

What we know - they are unquestionable:
(i) Machine reduces the spacing between the rows by half
(ii) Reduced spacing between the rows would reduce the yield per plant
(iii) Profits per acre would double

Profits increase when:
(i) Units sold increase while profits per unit sale don't fall, which follows an increase in production
(ii) Expenses per unit produced decrease, while sales remain the same


Costs of irrigation and of weed control will reduce. Also, the use of the adverb "costly" further strengthens this option. Keep (A) for now


We don't know whether the products of taller plants are more valued in the market. However, we are sure that taller plants, in this case, will not give a greater yield. This does not help. Reject (B)


This conflicts the argument mentioned earlier. Reject (C)


We are told that the yield per plant would drop. How much, we don't know. We don't know whether the drop would be more than half. Also, we cannot conclude anything about the change in expenses. Drop (D)


[/quote]
This is a technical detail and we are not aware about the impact of fallout years. Reject (E).

Therefore, the best answer is (A)

A new machine for harvesting corn will allow rows to be planted only fifteen inches apart, instead of the usual thirty inches. Corn planted this closely will produce lower yields per plant. Nevertheless, the new machine will allow corn growers to double their profits per acre because ________.

fifteen inches apart: Corn will produce lower yields per plant
new machine --> double profits per acre because

(A) with the closer spacing of the rows, the growing corn plants will quickly form a dense canopy of leaves, which will, by shading the ground, minimize the need for costly weed control and irrigation
This is the correct answer.
Profit = income - cost.
Cost 🠗 --> Profit 🠑

(B) with the closer spacing of the rows, corn plants will be forced to grow taller because of increased competition for sunlight from neighboring corn plants
No information about profit

(C) with the larger number of plants growing per acre, more fertilizer will be required
Profit = income - cost.
Cost 🠑 --> Profit 🠗

(D) with the spacing between rows cut by half, the number of plants grown per acre will almost double
Corn will produce lower yields per plant --> income 🠗

(E) with the closer spacing of the rows, the acreage on which corn is planted will be utilized much more intensively than it was before, requiring more frequent fallow years in which corn fields are left unplanted
requiring more frequent fallow years in which corn fields are left unplanted --> profit 🠗

I think many people reject the correct option A because after reading the first 10-12 words, they feel it's a lot of fluff that doesn't matter. They are probably thinking, "whether these plants form a canopy or now doesn't matter". They're right. This doesn't matter if this were the only thing given. However, the sentence builds upon this idea and ends up giving a financial advantage of this. What we can learn from this mistake is:

Don't reject an option on the basis of the first few words. Understand the whole sentence and then take a call whether it's right or not.


Option D is wrong because this information was already expected from the passage. The problem was that we had a lower yield per plant. So, even if the number of plants doubles, our yield of corn would not double. Then, how would our profits double? This option doesn't give any reason to answer this question.

Hi ChiranjeevSingh AnishPassi KarishmaB zhanbo

I am struggling to fully eliminate (D) because you can achieve your goal (of doubling profits per acre) within the given parameters in (D)

• Keeping costs the same, YOU DONT NEED your revenues to double to have profits double. It depends on your costs.
  
  Revenues can increase by as little as 50 % and still your profits CAN double (x 2)
  
  Linked is a simple mathematical example showcasing when revenues are increased by only 50 % (x 3/2), profits double (x2)

^^^^
ChiranjeevSingh AnishPassi KarishmaB zhanbo

Thus, with the information in (D) -- (D) allows for the possibility that revenues have increased by 70 % and profit/acre MORE THAN DOUBLED -- If the costs are low enough, an increase of revenues of 70 % is MORE THAN ENOUGH for profit/acre to double (> 100 % increase)

Why then is (D) still wrong when one could technically reach the desired result (of doubling profits/acre) within the parameters provided by (D) - it is mathematically possible to reach the goal .

jabhatta2, I am with you. It is possible to double or even triple profits with slightly improved production if the cost difference is negligible. (Actually, cost may be even lower, as (A) mentions.)

So, I guess that we eliminate (D) only because it does not really add any new information to what we already know. If (D) were to mention "with the spacing between rows cut by half, the number of plants grown per acre will almost double while the cost to grow them is only marginally higher". It should be a strong answer. Even if it says "...while the cost to grow them is only 50% higher", we can still defend it.

A hard question. Know the trick that if an answer choice does not add anything materially new, it cannot be the answer.

Rows will be planted 15 inches apart, not 30. So in the same area, one could theoretically plant almost twice the number of plants. But if plants are this close, their yields (per plant) will reduce. So we would think that the overall yield may increase but will not double.
Nevertheless, the author expects the PROFIT to double (mind you, not the yield).

Since profit depends on revenue as well as cost and revenue is expected to increase somewhat, the chances of profit doubling increase if cost is reduced too.
We need to find something that explains why profit will double (mind you, profit can double even if revenue doesn't double say revenue goes up from $100 to $150 and cost stays the same at $50. The profit goes up from $50 to $100)
Let's see which option provides us with support for profit doubling.

(A) with the closer spacing of the rows, the growing corn plants will quickly form a dense canopy of leaves, which will, by shading the ground, minimize the need for costly weed control and irrigation

This gives us reasons for why the cost would decrease. This gives good support to the conclusion that profit will double. Revenue will likely increase and cost will decrease. Certainly looks like profit will get a big push.

(B) with the closer spacing of the rows, corn plants will be forced to grow taller because of increased competition for sunlight from neighboring corn plants

If anything, this seems to say that the plants will withdraw more nutrition from the soil (perhaps explains why yield will reduce). It doesn't explain why profit may double.

(C) with the larger number of plants growing per acre, more fertilizer will be required

This is increasing the cost hence reducing profit, not increasing it.

(D) with the spacing between rows cut by half, the number of plants grown per acre will almost double

This is something we can already infer from the given data. If rows are planted at half the distance, we can plant an extra row between every two rows and hence, almost doubling the number of plants. But we are also given that the yield will decrease. The option doesn't help explain why profit may double.

(E) with the closer spacing of the rows, the acreage on which corn is planted will be utilized much more intensively than it was before, requiring more frequent fallow years in which corn fields are left unplanted

Out of scope. We are talking about the yield in the year when the crop is planted.

Answer (A)

You can, but does (D) support the doubling of profit? Whatever (D) says is something we can already infer from the argument. It provides no additional support for an increase in profit. The plants are doubling but the overall yield is not. We don't know how much the yield will be affected. If we move the other parameter (cost) also in favour of profit increasing, it increases our chances of profit doubling.

You are assuming fixed costs, regardless of the number of plants. And that is not a realistic assumption. As production increases, the cost of production usually increases too.

This is the argument:

Fact 1: The farmer is planting double the number of plants.
Fact 2: Corn planted this closely will produce lower yields per plants.
Puzzling prediction: Nevertheless, corn growers will double their profits per acre
Question: When the number of plants is doubled, how will profits double EVEN THOUGH yield per plant will not double?

Answer choice D is wrong because it does not answer the above question.

One way that profits can double is if costs are less than double the old costs. Another way is if selling prices are higher.

Answer choice A tells us that costs will not increase proportionately. None of the other answers gives us any reason to justify the prediction of doubled profits.

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