Sound waves travel slowest through gases.
Step-by-step explanation:
The three medium present are solids, liquids and gases or vacuum. Out of the three mediums, sound waves travels fastest through liquids as the sound waves can travel easily through liquid medium whereas compared to solids, they are little slower, but when compared to gases, slowest of all the mediums. Medium is one of the factor affecting the propagation of sound waves. Other factors includes temperature, pressure e.t.c.