A 025-M String,vibrating in Its Sixth Harmonic,excites a 0

Multiple Choice

A 0.25-m string,vibrating in its sixth harmonic,excites a 0.96-m pipe that is open at both ends into its second overtone resonance.The speed of sound in air is 345 m/s.The common resonant frequency of the string and the pipe is closest to

A) 540 Hz.
B) 360 Hz.
C) 450 Hz.
D) 630 Hz.
E) 700 Hz.