Aplumper charges $55 for a service call plus $35 per hour if the plumbers bill is $160 how many hour's was he thete

H= number of hours worked
Total= $160
Service call= $55
Hourly cost= $35

Total bill equals service call plus (hourly cost multiplied by number of hours worked)

$160= $35h + $55
subtract 55 from both sides
105= 35h
divide both sides by 35
3= h

ANSWER: The plumber worked 3 hours.

Hope this helps! :)