Question

Calculate he velociy of sound in gas in which the two sound waves of length 100cm and 101cm produce 24

Answer 1

f=vλ

In your problem, your have two different wavelengths, and hence two different frequencies. So you set up the wave equation for each:

f1=vλ1

and

f2=vλ2

You know λa and λ2. You need to find v. However, you have the beat frequency, which is exactly equal to the difference of the two frequencies, i.e.

f2−f1=12 Hz