Dear World,

If you work for a dealer or wholesaler who orders product from a manufacturer, you get a discount off the manufacturer's list price. Sometimes, when you order a custom item from the manufacturer, instead of quoting you a price, they will quote a percent upcharge on the list price. When this happens, you do not need to ask if the upcharge is to the list price or to your cost. It is the same thing. When you're multiplying a series of numbers, it doesn't matter in what order you do it. I will show you.

Let's say your discount is 50/10/10. That's a 59.5% discount; in other words, you pay 40.5% of the list price. Let's say you're buying something that lists for $753.00, and the custom modifications add 15% to the list price. Let's apply your discount first:

$753.00
x.405
$304.965

Now, let's apply the upcharge:

$304.965
x1.15
$350.70975, which we can round up to $350.71.

But wait! What if the upcharge is to the list price, not your cost?

$753.00
x1.15
$865.95
x.405
$350.70975, which we can round up to $350.71.

This has been your business math lesson for the day. Go forth and conquer!