Final answer:
To find the number of hours the plumber worked, set up an equation using the information given. Solve the equation to find the value of x, which represents the number of hours worked. The plumber worked for 2.5 hours.
Step-by-step explanation:
To find the number of hours the plumber worked, we can set up an equation based on the information given. Let's denote the number of hours worked as 'x'. The plumber charges $60 for every hour worked, so the cost for the hours worked would be $60x. In addition, there is a $40 charge for coming to the house. So the total cost would be $60x + $40. We know that the total cost is $190, so we can write the equation:
$60x + $40 = $190
To solve for x, we need to isolate the variable. We can start by subtracting $40 from both sides of the equation:
$60x = $190 - $40
$60x = $150
Next, we divide both sides by $60 to solve for x:
x = $150 / $60
x = 2.5
Therefore, the plumber worked for 2.5 hours.