So, if we take the information that we know, 1) The wall is 2 meters thick, and 2) it took a total of 0.05 seconds to travel all the way. So, to get our answer, lets divide 0.05 by 2. That lands us with 0.025! This answer makes sense, because we know that sound travels quickest in solids, (Due to sound-waves being a mechanical longitudinal wave, and solids have the densest particle formations, allowing the sound wave to travel swiftly compared to liquids and gases, in which the particles are more spread out.)
