Ecologist: The incidence of alligator attacks on humans in the vicinit

Ecologist: The incidence of alligator attacks on humans in the vicinity of the Blue Lagoon has increased in recent years. Relocating at least half of the Blue Lagoon`s alligator population would help decrease the incidence of alligator attacks on humans.

Type- Assumptions
Boil it down - Relocating at least half of the Blue Lagoon`s alligator population would help decrease the incidence of alligator attacks on humans.

A. Alligators prefer humans to other food sources. - Incorrect - Alligators might just attack and not eat humans

B. There is a correlation between the size of the alligator population and the incidence of alligator attacks on humans. - Correct - On negating this the argument falls apart

C. In recent years, there has been no significant change in the size of the alligator population in the Blue Lagoon. - Incorrect

D. Not all alligator attacks on humans are reported to authorities. - Incorrect - it only tells that ACTUAL numbers are higher

E. Relocating half of the lagoon`s alligator population would not be prohibitively expensive. - Irrelevant

Answer B

The objective: decrease the incidence of alligator attacks on humans.
How? : By relocating at least half of the Blue Lagoon`s alligator population

For the plan (relocating half of the alligator population) to actually result in a decrease in the incidence of alligator attacks on humans, there must be some sort of correlation between alligator population and incidents of attacks. If there was no correlation between the two, then executing the plan will never change the incidence of attacks.

Hence, the right answer would have to highlight this assumption (as shown in the highlighted text)

So, let us examine the available answer choices:

A. Alligators prefer humans to other food sources. - How does this statement help to achieve a decrease in the incidents of attacks on humans? It does not. Hence, eliminate (A).

B. There is a correlation between the size of the alligator population and the incidence of alligator attacks on humans. - BINGO. This fact establishes a direct link between the alligator population size and incidence of attacks. So, by relocation at least half of the alligator population, we can certainly expect a decrease in the incidence of alligator attacks on humans. Hence, (B) is the right answer.

C. In recent years, there has been no significant change in the size of the alligator population in the Blue Lagoon. -Okay. But how exactly does this statement relate to the outcome of the relocation plan? It doesn't! Hence, eliminate (C).

D. Not all alligator attacks on humans are reported to authorities. - this statement reiterates the threat of alligators, but it does not establish a direct link between the alligator population size and the incidence of alligator attacks. Hence, eliminate (D).

E. Relocating half of the lagoon`s alligator population would not be prohibitively expensive. - the expense of this plan is not related to its outcome in any way. hence, eliminate (E)

Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.