Answer :
The radio waves are electromagnetic wave, so it travels with velocity of light i.e [tex]3\times 10^{8} \ m/s[/tex].
We can use the relation between frequency, wavelength and speed as
[tex]\lambda =\frac{c}{f}[/tex]
Here c is speed of light, [tex]\lambda[/tex] is wavelength and f is frequency and its value is given 99.90 FM, it is actually in megahertz (i.e 99.90 MHz).
Therefore,
[tex]\lambda =\frac{3 \times 10^{8}\ m/s }{99.90 \times 10^{6} \ Hz} = 3.003 \ m[/tex].
Thus, the broadcast wavelength of the given radio station is 3.003 m.