Question

How to set up proportions if your discounted price is $163.80,the discount amount in $ is $31.20 but you don't know your % of discount and your original cost Please help

Answer 1

• original cost: $195.00
• % discount: 16%

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%.