Question

You have two sums that need to provide an equal result however I can not find the formula that will provide a consistent result.

We have a sales figure (A)
We have a commision percentage (B)
We have a commision total (C)
We have a net figure (D)

B of A = C
A - C = D

IE 10% of 1800 = 180, So the net figure is 1620

This sum is fine

However, in a second sum I need to add a credit card fee of 3.88%
Since the credit card fee has an impact on not only the sales figure but the commision, the adjusted sales price I need to create is always a variant of its original sales price and the commision percentage, figures that will always change.

Sum 2

We have a sales figure (A)
We have a fixed credit card fee percentage (X)
We have a commision percentage (B)
We have a commision total (C)
We have a net figure (D)

So in this case we are solving backwards, D in Sum 2 needs to be equal to D in Sum 1.

I just can't figure out what formula to use.

To give a practical example.

Sum 1
Sales Figure = 1800
Commision Percentage = 10%
Commision Total = 180
Net Figure = 1620

Sum 2
Sales Figure = 1881.10
Commision Percentage = 10%
Commision Total = 188.11
Credit Card Fee = 3.88% of Sales Figure, 72.99 total
Sales Figure - Commision Total - Credit Card Fee = Net Figure (the constant we need of 1620)

So, assuming that we will always know the Credit Card Fee, will always have a variable amount in the Sum 1 sales figure and Commision Percentage, how do I calculate a formula that will always make the Net Figure equal in both sums?

Answer 1