is there a formula for adding and subtracting percentages?

Question

Let's say I charge a customer $100.00 for an item. Now I'm going to get someone to help with my invoicing but this will cost me 10% of each invoice. So now I will only net $90.00 on my $100.00 invoice. So I decide to increase the cost to the customer, to compensate. But if I add 10% to $100.00, making the invoice $110.00, then

subtract the 10% "help" fee, it nets me only $99.00. How do I figure what to add to the $100.00 so that taking 10% off will result in the original $100.00 even?

Answer 1

Rich,

I suggests you create some kind of equation put variables for any unknowns or possibly working backwards.

Per my understanding, you want to charge extra so when you invoice you charge $100 after 10% is deducted.

$100 (amount you want returned) = 0.9x (x is the amount you need to charge and 0.9 is to deduct 10% )

100/0.9 = x (divide both sides by 0.9)

111.12 = x ( rounded up to the nearest cent which should return $100 after the 10% deduction)

Answer: You would add 11.12 to $100 so that after taking 10% off would result in the original $100

I hope this helps.

Please feel free to reach out if you still need me to clarify anything.

Thanks,

Richmond