How many coffee machines can one person manage on a full time basis?

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I realize many variables come into play here but I'm trying to get an idea about how much time it takes on average to manage and maintain coffee machines. To put things in perspective I've inquired about a coffee vending business which is for sale and I don't really know if the seller is providing a true representation of how much time it takes to run the business. 

He has 84 sited machines, of which 15 are out due to Covid. He claims to work 4 days per week from about 9:30 AM to 2:30 PM. A few machines he services on a weekly basis but most are on a fortnightly basis. The machines are spread over a fairly large area (Melbourne, Australia which to provide some perspective has a population of 5 million). I guess you can't really drag it out any longer than a couple of weeks otherwise the beans would start to go stale.

Do you think this is a realistic time commitment for one person to run a business of this size?