I want to talk about different ways of characterizing a credit card surcharge.
If a company wants to recoup all the money it has to pay Visa for accepting credit cards, it may charge an amount equal to what Visa skims off the top -- let's say 3%.
So if a cheeseburger costs \$10 cash and \$10.30 credit, they'd say that there was a 3% surcharge on all credit transactions. But what if they wanted to say that there was a discount for people who use cash, without changing the prices? To get from $10.30 to the number that it is 3% more than, you'd apply a 2.91% discount. If Visa were charging 5%, you'd discount by 4.76%.
I'm trying to talk about the relationship between the credit card surcharge and the cash discount. Is there a word that names that relationship so I could ask you to calculate the [blabla] of 3 and 5 and you'd tell me 2.91 and 4.76?