Critical Reasoning

As a construction material, bamboo is as strong as steel and sturdier than concrete. Moreover, in tropical areas bamboo is a much less expensive construction material than either steel or concrete and is always readily available. In tropical areas, therefore, building with bamboo makes better economic sense than building with steel or concrete, except where land values are high.

Which of the following, if true, most helps to explain the exception noted above?

(A) Buildings constructed of bamboo are less likely to suffer earthquake damage than are steel and concrete buildings.
(B) Bamboo is unsuitable as a building material for multistory buildings.
(C) In order to protect it from being damaged by termites and beetles, bamboo must be soaked, at some expense, in a preservative.
(D) In some tropical areas, bamboo is used to make the scaffolding that is used during large construction projects.
(E) Bamboo growing in an area where land values are increasing is often cleared to make wayfor
construction.

[spoiler]OA: B[/spoiler]

Hi,
Can you please let me know why B is the right answer and why E is not ?

P.S: Mitch/Brent/Jim and other Verbal experts - I'd really appreciate your detail explanation in this regard. Thank you!

Hi RBBmba@2014,

As you noted, the correct answer is B. Let's look at all the answers in more detail:

(A) Buildings constructed of bamboo are less likely to suffer earthquake damage than are steel and concrete buildings.
Incorrect. There is no relationship between "bamboo buildings surviving earthquake damage," and "bamboo not used in areas with high land values" (the exception we are seeking to explain).

(B) Bamboo is unsuitable as a building material for multistory buildings.
Correct. There is a relationship between "bamboo not suitable for multi-story buildings," and "bamboo not used in areas with high land values." The relationship is that in areas with high land values, multi-story buildings are the norm, because you can build many homes within a small area of land (by building upwards, rather than outwards). If bamboo is not suitable for multistory buildings, then it explains the exception, i.e. bamboo not used where land values are high.

(C) In order to protect it from being damaged by termites and beetles, bamboo must be soaked, at some expense, in a preservative.
Incorrect. This answer is irrelevant to the exception.

(D) In some tropical areas, bamboo is used to make the scaffolding that is used during large construction projects.
Incorrect. This answer is irrelevant to the exception.

(E) Bamboo growing in an area where land values are increasing is often cleared to make way for construction.
Incorrect. At first it seems like this might be a logical choice. However, if true (and we must accept it as true), it does not MOST help to explain the exception of bamboo not used in areas where land values are high. Even if bamboo is often cleared in these areas, it could still be easily available (just as steel and concrete could be easily available even though they are not likely endemic to the area, i.e. they have to be brought in to the building site from somewhere else).

I hope this helps.

Much thanks David for your detail explanation and analysis.

David@GMATPrepNow wrote:.

(B) Bamboo is unsuitable as a building material for multistory buildings.
Correct. There is a relationship between "bamboo not suitable for multi-story buildings," and "bamboo not used in areas with high land values." The relationship is that in areas with high land values, multi-story buildings are the norm, because you can build many homes within a small area of land (by building upwards, rather than outwards). If bamboo is not suitable for multistory buildings, then it explains the exception, i.e. bamboo not used where land values are high.



I hope this helps.

There are no options better than B, but doesn't it require a leap of logic on GMAT to say that multistorey buildings correspond to high land values ?

gocoder wrote:

David@GMATPrepNow wrote:.

(B) Bamboo is unsuitable as a building material for multistory buildings.
Correct. There is a relationship between "bamboo not suitable for multi-story buildings," and "bamboo not used in areas with high land values." The relationship is that in areas with high land values, multi-story buildings are the norm, because you can build many homes within a small area of land (by building upwards, rather than outwards). If bamboo is not suitable for multistory buildings, then it explains the exception, i.e. bamboo not used where land values are high.



I hope this helps.

There are no options better than B, but doesn't it require a leap of logic on GMAT to say that multistorey buildings correspond to high land values ?

You don't have to make much of a logic leap here. You just have to realize that a multi-story building can produce more rent revenue than a single-story building. If you pay a lot to acquire the land, you'll need to generate more revenue to justify the cost, right? So you'd be more inclined to build a multi-story building in these areas.