Question

qasdff

Short answer

The sound speed is 170 Hz.

Step-by-step solution

Understanding sound speed  

The speed at which sound waves propagate through different materials

Explanation of the solution 

The distance of the speaker is 12m by the Pythagorean theorem. Thus, the triangle is $\sqrt{{12}^2+5^2}=13m$

The difference in the path is $2\mathrm{\pi }\frac{∆\mathrm{x}}{\mathrm{\lambda }}=\mathrm{\pi }$

Then the wavelength frequency is $\lambda =2∆x=2.1=2m$

The frequency is$f=\frac{v}{\lambda }=\frac{340}{2}=\boxed{170Hz}$