Statistics question on classical probability?

I am taking Business Statistics, this is the problem:

Electric meters on private homes in a community register the cumulative consumption of kilowatt-hours with a five-digit reading. If a home in the community was randomly selected, it’s possible that the right-hand digit (which spins the fastest) would be a “7”. Using the concept of classical probability, what is the probability that the digit is a “7”?

How would this be solved?

Please use layman's terms, I have very little math skills.