Hand written solution required

Advanced Physics A clever plumber knows that a hollow copper pipe is open at one end, the end he can access, and closed at the other end. which he cannot see because it is going through a wall into an adjoining room. Using a speaker directed into the open end and driven by a tone generator, he finds that one of the harmonics has a frequency of 448 Hz and the next higher harmonic has a frequency of 576 Hz. How long is the pipe? A 0.670 m B 0.335 m c 2.68 m D 1.00 m E) 1.34 m b. How does you answer change if the pipe is open at both ends