Frequency of p th overtone of open organ pipe =(p+1)2Lv...(i)
where, L= length of organ pipe and that of closed organ pipe is =(2p+1)4LV...(ii)
So, the ratio of p th overtone of open to closed =(2p+1)4Lv(p+1)2Lv (using Eqs. (i) and (ii) =(2p+1)2(p+1)