Critical Reasoning

11. "If the forest continues to disappear at its present pace, the koala will approach extinction," said the biologist.
"So all that is needed to save the koala is to stop deforestation," said the politician.
Which one of the following statements is consistent with the biologist's claim but not with the politician's claim?
(A) Deforestation continues and the koala becomes extinct.
(B) Deforestation is stopped and the koala becomes extinct.
(C) Reforestation begins and the koala survives.
(D) Deforestation is slowed and the koala survives.
(E) Deforestation is slowed and the koala approaches extinction.

IMO the answer in D. Please correct me if I'm wrong.

I agree that it should be D

IMO the answer is B.

This directly refutes that politicians claim, while is at least consistent with the biologists claims.

The reason I say its consistent with the biologist's claims is that the biologist says;

If deforrestation continues, koalas will approach extinction. - From this the only other thing we can deduce is;

If koalas do not approach extinction, deforrestation has not continued.

B says deforrestion has not continued and the koalas have become extinct. This supports the biologists claim because the biologist says that if deforrestation continues the koalas will approach extinction. There is a difference in becoming extinct and approaching extinction. What if, for some freak reason, the stopping of deforrestation actually caused all the pandas to die immediately? This would support the biologist because the biologist didn't say anything about what would happen if deforrestation stopped. Thus, B at least is consistent with the biologist.

What is the official answer?

Note that the biologists does NOT say what will happen if deforestation is slowed. Do not confuse a necessary condition with a sufficient one!

i went with C because it opposes Politicians idea of stopping deforestation, instead it proposes the opposite . At the same time choice C goes with biologist "the koala survives"..what did i miss??

In the post https://www.beatthegmat.com/cr-1000-t3251.html Stuart Kovinsky clearly explained the logic.

I am just rewriting it here:
Biologist: If deforestation, then K extinct - doesn't mean deforestation is THE ONLY reason but says it is one of the reasons
Politician: If no deforestation, then K not extinct - means deforestation is THE ONLY reason.

Our option should say :
deforestation is stopped and still K approaches extinction to be not consistant with Politician.

So we are left with B and D.
However D doesn't say deforestation stopped. It has to be "stopped" in order to refute politician's view.

HTH. Thanks

Hi,

If we note the politicians statement: "So all that is needed to save the koala is to stop deforestation", we find that the necessary condition, indicated by the word needed is referring to the action stop deforestation

So shouldn't the diagram read as follows -

If K not extinct, then no deforestation
(sufficient: If K not extinct -----> necessary: no deforestation)

I cant get my head around this!!

Any help is most appreciated.

Sid.

kevincanspain wrote:Note that the biologists does NOT say what will happen if deforestation is slowed. Do not confuse a necessary condition with a sufficient one!

Please elaborate this & how D is incorrect

vikram4689 wrote: Please elaborate this & how D is incorrect

Politician's claim: So all that is needed to save the koala is to stop deforestation

D, which says: "Deforestation is slowed and the koala survives" is not inconsistent with Politician's claim.

This is basically what politician is saying: If there is no deforestation, Koala will survive.

Politician's claim: So all that is needed to save the koala is to stop deforestation IMPLIES Koala can be saved only be stopping deforestation

Now D says Koala can be saved by slowing deforestation. Isn't it inconsistent, what am i missing

Anyone who would like to give it a shot !