
Count how much will Carmen earn when she works only 40 hours:
$7.80·40=$312.
Since $312 < $352.95, then Carmen should have worked extra hours.
The difference in payment is
$352.95 - $312 = $40.95 - the amount of money Carmen earned while working extra hours.
An extra hour is paid $3.90. If she earned $40.95 for all extra hours, then she had worked
$40.95 : $3.90 = 10.5 extra hours.
Answer: 40 regular hours and 10.5 extra hours. In total, 50.5 hours. Â