Service Charge Calculating on the price with Service Charge

V5 Question
1

All My prices have service charge included now in this calculation I want it to calculate from less 10%. Help how I can make it calculate from price with less 10%.

[Payments:1, 1, 1, 1]

Payment|Net|Service Charge|Total
{REPORT PAYMENT DETAILS:P.Type,[$4-($40.01)];0.00,[$40.01];0.00,P.Amount.Sum}
Total|{REPORT PAYMENT DETAILS:=[$3-($30.01)];0.00,[$30.01];0.00,P.Amount.Sum}

2

There is a tutorial on that

Hope that helps