Answer:
A pipe open at both ends would have an antinode at each end and its length would be λ/ 2
The next such points would be λ and 3 λ / 2
The ratio of 522 / 348 is 1.5 so the harmonic at 348 is one wavelength and the next harmonic is 3 λ / 2 at 1 1/2 wavelengths
348 hz would occur at one wavelength
f λ = v = f L where the length of the pipe is one wavelength
if we use 331 as the speed of sound then
L = 331 / 348 = .95 m for the length of the pipe