Which statement with respect to the speed of sound is correct ?

Question

ATPL - Airline Transport Pilot license - Principles of Flight - Which statement with respect to the speed of sound is correct ?

QuizVDS · Accepted Answer

Varies with the square root of the absolute temperature.

QuizVDS · Answer

Doubles if the temperature increases from 9° to 36° Centigrade.

QuizVDS · Answer

Is independent of altitude.

QuizVDS · Answer

Increases always if the density of the air decreases.

ATPL: Which statement with respect to the speed of sound is correct ?