Answer:
[tex]f = 132\,hz[/tex]
Explanation:
The speed of the sound wave is:
[tex]v = \frac{660\,m }{2\,s}[/tex]
[tex]v = 330\,\frac{m}{s}[/tex]
The frequency is:
[tex]f = \frac{v}{\lambda}[/tex]
[tex]f = \frac{330\,\frac{m}{s} }{2.5\,m}[/tex]
[tex]f = 132\,hz[/tex]
