Skip to main content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

Math help from the Learning Centre

This guide provides useful resources for a wide variety of math topics. It is targeted at students enrolled in a math course or any other Centennial course that requires math knowledge and skills.

Multiple Rates of Discount

undefined

undefined

How to use the formulas?

Example: An item values at $28 after discount. If a trade discounts series of 25%, 15%, and 10% were offered, find the original price.

What do we know? $28 is value after discounts ⇒ this is the net price (N = $28). There are multiple discounts (25% = 0.25, 15% = 0.15, 10% = 0.10).

What are we looking for? We are looking for the original price before discounts ⇒ find the list price.

undefined

The original price was $48.80.

Multiple Rates vs Single Rate

Why are the multiple discounts of 25%, 15%, and 10% not the same as 25% + 15% + 10% = 50%?

undefined

Whereas the sum of discounts 50% of $100 equals $50.

To find the single rate from multiple rates. Use the formula.

d = 1 - (1 - 0.25)(1 - 0.15)(1 - 0.10) = 0.42625 or 42.625%

chat loading...