When a metal pipe is cut into two pieces, the lowest resonance frequency in one piece is 244Hz and that for the other is 454Hz. What resonant frequency would have been produced by the original length of pipe? (Assume the speed of sound in air is 345 m/s)

^ I already got the answer for this one: 1.59×102 Hz

but please help me with part b

b)How long was the original pipe?