A radio can tune to minimum frequency,

ν₁ = 7.5 MHz= 7.5 x 10⁶ Hz Maximum frequency,

ν₂= 12 MHz = 12 x 10⁶ Hz,

Speed of light, c = 3 x 10⁸ m/s

Corresponding wavelength for ν₁ can be calculated as:

λ₁=c/ν₁ = (3 x 10⁸)/( 7.5 x 10⁶ ) =40m

Corresponding wavelength for ν₂ can be calculated as:

λ₂=c/ν₂ = (3 x 10⁸)/( 12 x 10⁶ ) =25m

Thus, the wavelength band of the radio is 40 m to 25 m.