1. The problem statement, all variables and given/known data Two organ pipes, open at one end but closed at the other, are each 1.18 m long. One is now lengthened by 2.50 cm 2. Relevant equations λ = nL/4 fn = nv/4L v = λF 3. The attempt at a solution Here's what I tried First I tried finding the fundamental frequency when their lengths were equal f = (1)(343 m/s)/4(1.18m) f = 72.66949153 Hz I'm assuming that v = 343 m/s. It does not say that this is the case in the problem. Then I tried finding the frequency of the pipe with the extension fextended = (1)(343 m/s)/4(1.205m) fextended = 71.16182573 Hz Having found these two frequencies I then took of the average of them which gave me 71.916 Hz. Unsurprisingly this didn't work. Any suggestions?