A String That Is 0

Multiple Choice

A string that is 0.26 m long is vibrating in its n = 6 harmonic. The sound from this string excites a pipe that is 0.88 m long and open at both ends into its second overtone resonance. What is the
Common resonant frequency of the string and the pipe? The speed of sound in air is 345 m/s.

A) 490 Hz
B) 760 Hz
C) 690 Hz
D) 390 Hz
E) 590 Hz