An electrician charges $60 as a one-time fee plus an additional $55 per hour. If the total bill is $252.50, how many hours did it take for the electrician to complete the repair?

If he arrived at 10:30 a.m., what time was he finished with the repair? Show calculations.

1 answer

To determine how many hours it took for the electrician to complete the repair, we can set up an equation based on the pricing structure given:

The total bill is the sum of the one-time fee plus the hourly rate times the number of hours worked. The equation can be represented as:

\[ \text{Total Bill} = \text{One-time fee} + (\text{Hourly rate} \times \text{Hours}) \]

Substituting the values we have:

\[ 252.50 = 60 + (55 \times h) \]

where \( h \) is the number of hours worked.

Now, we can solve for \( h \):

  1. Subtract the one-time fee from both sides:

\[ 252.50 - 60 = 55h \]

\[ 192.50 = 55h \]

  1. Now, divide both sides by 55 to isolate \( h \):

\[ h = \frac{192.50}{55} \]

Calculating the result:

\[ h = 3.5 \]

So, it took the electrician 3.5 hours to complete the repair.

Finding the Finish Time

If the electrician arrived at 10:30 a.m. and worked for 3.5 hours, we can calculate the finish time by adding 3.5 hours to the arrival time.

  1. Convert 3.5 hours into hours and minutes.

3.5 hours is equivalent to 3 hours and 30 minutes.

  1. Starting from 10:30 a.m., add 3 hours:
  • 10:30 a.m. + 3 hours = 1:30 p.m.
  1. Now add 30 minutes to 1:30 p.m.:
  • 1:30 p.m. + 30 minutes = 2:00 p.m.

Thus, the electrician finished the repair at 2:00 p.m.

Summary:

  • The number of hours worked: 3.5 hours
  • Finish time: 2:00 p.m.