Question

An electrician charges a flat fee plus an hourly rate for a service call. She charges a total of $94 for a 3-hour service call on Monday and $130 for a 5-hour service call on Tuesday. How much should she charge for a 2-hour service call?
$36
$52
$76
$98

Answer 1

Let F be the flat fee and r the hourly rate.
F + 3r = 94
F + 5r = 130
Subtract: 2r = 36 → r = 18
Then F = 94 − 3(18) = 40
For 2 hours: F + 2r = 40 + 36 = 76

Answer: $76