A development company has proposed building an airport near the city of Dalton. If the majority of Dalton's residents...

Samuel on December 1, 2016

Y idnt

Y i dont get it

3 Replies

Mehran on December 1, 2016

@samuel let's break down the argument here:

"If the majority of Dalton's residents favor the proposal, the airport will be built."

PR: MDRF ==> AB
not AB ==> not MDRF

"However, it is unlikely that a majority of Dalton's residents would favor the proposal, for most of them believe that the airport would create noise problems."

P: not MDRF

"Thus, it is unlikely that the airport will be built."

C: not AB

The flaw here is that the author is taking the non-existence of the sufficient condition to conclude the non-existence of the necessary condition.

But we know that you DON'T JUST NEGATE!

Stated another way, the author is mistaking sufficient for necessary as follows:

PR: AB ==> MDRF
not MDRF ==> not AB

P: not MDRF

C: not AB

As such, (A) would be the correct answer choice.

Hope that helps! Please let us know if you have any other questions.

on May 31, 2018

Why is C wrong?

Christopher on June 6, 2018

@meisen, there is nothing in the question that refers to the likelihood or unlikelihood of the airport being built other than the actual conclusion, which is "it is unlikely to be built." The flaw in the logic is that the author concludes that if the majority of residents want the airport to be built, it will be built to mean that if the majority of residents do not want the airport to be built, it will not be built. It is possible that a majority oppose the airport but that it still be built, therefore (A) is the correct answer.