Answer:
72.225 $
Step-by-step explanation:
The price per pack: 5.00 $
When the amount of packs is > 10 :
90 % * 5 $ = 4.50 $ before tax.
The price of 15 packs:
4.50 $ * 15 = 45 + 22.5 = 67.5 $ before tax.
After tax:
107 % * 67.5 $ = 72.225 $ after tax.
