Answer:
- original cost: $195.00
- % discount: 16%
Step-by-step explanation:
I wouldn't mess with trying to set up proportions. That seems an inappropriate tool for this. Instead, make use of the known relationships between the various prices:
original cost - discount amount = discounted price
Adding the discounted amount to both sides of this equation gives ...
original cost = discounted price + discount amount
original cost = $163.80 + 31.20
original cost = $195.00
_____
The percentage discount is ...
percent discount = (discount amount)/(original cost) × 100%
= $31.20/$195.00 × 100%
= 16%
The percentage discount is 16%.
