Say you have to serve 500 customers within a 4 hour time frame. You know that 1 taxi can provide 1 ride an hour, hence 1 taxi can provide 4 rides in that time-frame. How many taxis would you need to serve these customers?

I know that you are supposed to do 500/4, but can someone just break this down for me? I simply don't seem to understand why you would divide. I'm confused at how you can divide 500 customers/4 rides, as the units don't fit with each other.

Thanks!