Sajjad1994 wrote:
Efficiency and redundancy are contradictory characteristics of linguistic systems: however, they can be used together to achieve usefulness and reliability in communication. If a spoken language is completely efficient, then every possible permutation of its basic language sounds can be an understandable word. However, if the human auditory system is an imperfect receptor of sounds, then it is not true that every possible permutation of a spoken language’s basic language sounds can be an understandable word.
If all of the statements above are true, which one of the following must also be true?
(A) Efficiency causes a spoken language to be useful and redundancy causes it to be reliable.
(B) Neither efficiency nor redundancy can be completely achieved in spoken language.
(C) If a spoken language were completely redundant, then it could not be useful.
(D) If the human auditory system were a perfect receptor of sounds, then every permutation of language sounds would be an understandable word.
(E) If the human auditory system is an imperfect receptor of sounds, then a spoken language cannot be completely efficient.
OFFICIAL EXPLANATION
This is a rather challenging question. To solve it, we’ll use both the transitive property and the contrapositive. The sentence “
If a spoken language is completely efficient, then every possible permutation of its basic language sounds can be an understandable word” can be symbolized as
CE—>EPU
where CE stands for “
completely efficient,” and EPU stands for “
every permutation is understandable.”
Forming the contrapositive of this expression gives
~EPU—>~CE
Next, the sentence “
if the human auditory system is an imperfect receptor of sounds, then it is not true that every possible permutation of a spoken language’s basic language sounds can be an understandable word” can be symbolized as
IR—>~EPU
Now combining this expression with the contrapositive formed above gives
IR—>~EPU—>~CE
Then simplifying using the transitive property gives
IR—>~CE
Writing this express out gives “
If the human auditory system is an imperfect receptor of sounds, then a spoken language cannot be completely efficient.” This is an exact quote of choice (E) and therefore
(E) is the answer.