The velocity of sound in air (under normal condition) is

30 m/sec
320 m/sec
332 m/sec
3,320 m/sec

The velocity of sound in air (under normal condition) is 332 m/sec. This means that sound travels at a speed of 332 meters per second in air at a temperature of 20 degrees Celsius and a pressure of 1 atmosphere.

Option A is incorrect because the velocity of sound in air is not 30 m/sec.

Option B is incorrect because the velocity of sound in air is not 320 m/sec.

Option C is correct because the velocity of sound in air is 332 m/sec.

Option D is incorrect because the velocity of sound in air is not 3,320 m/sec.