The fundamental frequency of the open organ pipe is 300 Hz.The frequency of the first overtone of the another closed organ pipe is the same as the frequency of the first overtone of open pipe.What are the length of the pipes ?? The speed of the sound is=330ms^-1.

Fundamental freq= v/2L= 300 Hz

so first overtone= v/L = 600 Hz

given:- 1st overtone of open pipe = 1 st overtone of closed pipe

So 600=3v/4L (since 1st overtone of closed pipe is 3v/4L)

or L= 3*330/4*600L= 0.4125 m or 41.25 cm

For length of open pipe--

600 = v/L

so L= 600/v = 600/330 = 1.81 m or 181 cm..

hope it helps :-)