Basic Harmonic Frequencies Question

[armolinasf]

Homework Statement

A string is stretched between fixed supports separated by 82.0 m. It is observed to have resonant frequencies of 334.000 and 389.667 Hz, and no other resonant frequencies between these two.

A)What is the lowest resonant frequency of the string?

B)What is the wave speed of this string?

The Attempt at a Solution

I guess I don't really understand this question, Isn't 334 Hz the lowest frequency?

 

[Spinnor]

Call the fundamental frequency F, then the higher harmonics of the string will have frequencies 2*F, 3*F, 4*F, ...

What you know is m*F = 334.000 Hz, and (m+1)*F = 389.667 Hz

(m+1)*F - m*F = ?