Calculation done for only one hour.
Ignores pickup, return and parts costs ($50 + $30).

Next steps:

Extension:

Mrs Daniels wanted to get her computer fixed. No parts were needed. All three firms would charge her the same total amount for repairs (including pickup and return).

How long would Mrs Daniels repairs take? (Answer: 1.5 hours)

Plot a graph of how much each firm would charge in total for a variety of different times to fix computers if there were no parts needed. What do you notice about the three graphs. (Answer: They are straight lines that meet at the point (1.5, 150).)