Alright here's the breakdown
take ($8) and (40hr.) and multiply them (8 x 40)
which should equal
$320
but that's not enough
so
we need to add some hours
so
take the numbers like this ($380-$320)
which should equal
$60
now
take ($60) and divide it by the overtime pay ($12 per hr.)
which equals
the number of overtime hours needed to achieve her goal
which is
(5 hr.)
which is your answer
hope this helps!