First calculate how much money Biff spent getting ready for the trip: $11 + $3 + $16 = $<<11+3+16=30>>30
Now calculate Bill's net income per hour after he pays for WiFi by subtracting the WiFi cost from his gross hourly rate: $12/hr - $2/hr = $<<12-2=10>>10/hr
Finally, divide the money Bill spent by his net hourly rate to find out how many hours he has to work to break even: $30 / $10/hr = <<30/10=3>>3 hours
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