Wave Velocity

Q. How long does it take for a sound wave of frequency $2kHz$ and a wavelength of $35cm$ to travel a distance of $1.5km$?

1. $3sec$
2. $2.3sec$
3. $1.9sec$
4. $2.1sec$

Q. A sound wave is propagating as shown below. What is the speed of sound wave?

1. $1/3cm/sec$
2. $1cm/sec$
3. $0.5cm/sec$
4. $2cm/sec$