8. A plumber worked ten hours at $15 per hour. How many hours does she have to work at $20 per hour in order to average $18 per hour?
h represents: _____________________________________
h represents the number of hours the plumber has to work at $20 per hour.
8. A plumber worked ten hours at $15 per hour. How many hours does she have to work at $20 per hour in order to average $18 per hour?
What equation can be used to solve this problem
To solve this problem, we can use the equation for calculating average rate:
Average rate = Total earnings / Total hours worked
Let's set up the equation using the given information:
$18/hour = (total earnings at $15/hour + total earnings at $20/hour) / (10 hours + h hours)
Since we know the total earnings at $15/hour is $15/hour x 10 hours and the total earnings at $20/hour is $20/hour x h hours, the equation becomes:
$18/hour = ($15/hour x 10 hours + $20/hour x h hours) / (10 hours + h hours)
Now we can solve for h.
A plumber worked ten hours at $15 per hour. How many hours does she have to work at $20 per hour in order to average $18 per hour?
To solve this problem, we can set up an equation using the concept of average rate:
Average rate = Total earnings / Total hours worked
Let's use the given information to set up the equation:
$18/hour = (total earnings at $15/hour + total earnings at $20/hour) / (10 hours + h hours)
The total earnings at $15/hour is $15/hour x 10 hours = $150.
Let's substitute the values into the equation:
$18/hour = ($150 + $20/hour x h hours) / (10 hours + h hours)
Now, let's simplify the equation:
$18/hour = ($150 + $20h) / (10 + h)
To solve for h, we can cross-multiply:
$18/hour * (10 + h) = $150 + $20h
180 + 18h = 150 + 20h
Now, let's isolate the variable h:
18h - 20h = 150 - 180
-2h = -30
h = -30 / -2
h = 15
Therefore, the plumber needs to work 15 additional hours at $20 per hour in order to average $18 per hour.
15 * 10 + 20h / 10 + h = 18
Actually, there seems to be a mistake in your equation. The correct equation should be:
(150 + 20h) / (10 + h) = 18
Let me solve this equation for you.
First, let's cross multiply to eliminate the fraction:
18(10 + h) = 150 + 20h
180 + 18h = 150 + 20h
Next, let's simplify the equation by grouping the variables on one side:
18h - 20h = 150 - 180
-2h = -30
Finally, let's solve for h:
h = (-30) / (-2)
h = 15
Therefore, the plumber needs to work 15 additional hours at $20 per hour in order to average $18 per hour.