Answer
Lecture cost = $7.33 each hour
Explanation
Let
denote the expense for exam hours.
Let
signify the expense for workshop hours.
Let
indicate the expense for lecture hours.
The problem states that exam hours are priced at double that of workshop hours, represented by:
equation (1)
It also indicates that workshop hours are at twice the cost of lecture hours, exemplified by:
equation (2)
In addition, we understand that the combined cost for 3 hours of exams, 24 hours of workshops, and 12 hours of lectures totals $528, represented as:
equation (1)
Now, let’s compute the value of
:
Step 1. Determine
via equation (3)

equation (4)
Step 2. Substitute equation (1) into equation (4) and simplify



equation (5)
Step 3. Insert equation (2) into equation (5) and solve for 







Lecture cost = $7.33 every hour