direct proportionality formula:
y = kx
where: y varies directly on x by k, the constant of proportionality;
In this problem, we substiture k with p.
y = total earning
p = hourly rate
x = no. of hours worked
y = 108
p = ?
x = 12 hrs
y = px
108 = p(12)
108/12 = p(12)/12
p = 9 hourly rate or rate per hour.
p = y/x
p = $108 / 12hrs
