Answer
The answer and procedures of the exercise are attached in the following archives.
Step-by-step explanation:
You will find the procedures, formulas or necessary explanations in the archive attached below. If you have any question ask and I will aclare your doubts kindly.
Nikkis charges are 20,40,50,80. Dave’s charges are 25 and 37.5.
70.4
The word "of" means to multiply, so 22% or .22 * 320 = 70.4