Generate result based on selected text

Hello, everybody! I need your help! 🙂

Please see the attached image. I have to calculate de Gross salary from Net and we have 2 situations:

1. when the gross salary is calculated normally
2. when the gross salary receives a 10% deduction from the government (special cases).

This means I am using 2 different formulas to generate the result based on this 10% deduction. One formula without the 10% deduction support from the government and another formula including the 10% deduction.

Is it possible that these 2 formulas change automatically depending on the YES or NO text that wil be selected in the dropdown list? I mean if I will select NO, we will have the normal gross salary formula calculation but if I select YES, the formula calculation will change and it will automatically generate the result with 10% deduction.

I don’t know if this is possible or not. I have searched everywhere but found no solution. Maybe someone will be able to help. Thank you very much! 🙂