# Math Help - Calculating added percentages

Hello everyone, I imagine this has been queried before but I've not been able to find a clear understandable (to maths dummy me) answer, if someone could help I'd be grateful.

I have to invoice a fee to a Japanese client which includes 20% tax which the Japanese government deducts at source. i.e. 20% will be deducted from the total invoice amount, not the fee I'm to receive.

eg. say my fee is 10,000 yen. If I calculate 20% of that and invoice 12,000 yen the total value of the invoice has increased. The tax office would deduct 20% from 12,000 yen, so I'd only receive 9,600 yen.

So how do I calculate the correct percentage?

Many thanks!

2. $12,000 \times x = 10,000$

$x = \frac{5}{6}$

You can use this $\frac{5}{6}$ as your multiplier

3. Thank you pickslides, I'm sorry but I still don't understand, could someone clarify?

Many thanks!

4. I think pickslides misunderstood your question.

If I understand the question correctly, you want to set your fee so that after 20% is subtracted, you will have $10000. Let "x" be the amount charged. The 20% of that is 0.20x. After subtracting that you will have left x- 0.20x= (1- .20)x= 0.80x= 10000. Solve for x by dividing both sides by 0.80: x= 10000/0.80= 12500 You should charge$12500.

Then 20% of 12500= 0.20*12500= 2500 and 12500- 2500= 10000.

5. HallsofIvy, thank you! That's exactly what I was looking for.