Answer:
91 hours
Step-by-step explanation:
Add 12 to itself 8 times and then add 7 once
y=8/(P+q+4)
we can find out that three items have y
so we can get them together Py+qy+4y=8
next(P+q+4)y=8 so y=8/(p+q+4)
$24
You simply do $42-$18
=24