Critique here:

The audio has a couple loud bangs, the first of which scared me to death because I thought something hit my car! Filter and/or re-record mic drops recommended :D

Second, it was a good story but I really would have liked to have a go at solving the problem myself before it was explained to the friends. Perhaps you could have given us, the reader, the problem first and the entire thought process of solving it, with the end of that explanation containing the solution, perhaps that's where you could cut in and explain the solution to the friends. That way if we the readers figure it out ahead of the narration then we get that little bump of dopamine!