Answer: 1.33 metres
Step-by-step explanation:
Given that:
Wavelength (λ)= ?
Frequency F = 256Hz
Speed of sound wave = 340 m/s 
So, apply the formula:
Wavespeed = frequency x wavelength 
i.e V = F λ
340m/s = 256Hz x λ
λ = (340m/s ➗ 256Hz)
λ = 1.328 m (Round to the nearest hundredth which is 1.33 m) 
Thus, the wavelength of a sound wave is 
1.33 metres