A 1289 Hz sound from the speaker enters a tube at point A.

It then takes two paths, ACD or ABD. Minimum sound is heard when ACD has a length of 94.2 cm and ABD has a length of 41.0 cm. The length of ACD is slowly increased until the point of maximum loudness is found when ACD is 108 cm (ABD is left unchanged). What is the speed of sound?

The answer for the speed of sound is 343 m/s but i have no idea how to get it. i keep getting 355 m/s