“I heard you have a new job, Dirk,” said Barney, taking a sip of his beer.
“Yea, I do, Barney, and it’s a really great job because I get a lot of time off to go fishing at the lake,” said Dirk Burton, master electrician, with a big grin on his face.
“Tell me all about it,” replied Barney – all ears.
“I’m working standby 24/7 for Acme Hot-Plug Electronics, Inc., a large company with many branches. They have an average of seven emergencies per week that they want me to handle,” explained Dirk, gulping down a large swig from his tall mug of beer.
“But that’s crazy, working 24/7. How do you get any time to go fishing?” asked an incredulous Barney, downing a big swig too.
“No problem, Barney. As the number of emergencies to be handled is logged by midnight, the next morning they let me know by 8 am via SMS how many there are for me that day. If they don’t need me, I get the day off,” explained Dirk, ordering another beer.
“I get it. You could get up to seven emergencies in a day, or none at all,” said Barney.
“That’s the deal,” said Dirk, “with no emergencies reported, I hang up my ‘GONE FISHING’ sign on the front door and head for the lake. From there I check the phone until they need me.”
“Wow, that’s the life,” exclaimed Barney filled with admiration, and finishing his beer, “got any fish for sale?”
Can you work out the probability that Dirk will have at least three days off during any week?
How many weeks, on the average, do you think Dirk would have to work to experience one single day with seven emergencies?