Wrong Price calculation

Hello,

i have a problem with the price calculation.
We rent appartements for 2-3 Persons.
The rent price for 2 persons is: 59€
If there is a 3th adult it comes an extra charge of 12.
If the 3th person is a child there is an extra charge of 10.33.

So the calculation should be:
1. 3 Persons: 71
2. 2 Adults + 1 Child: 69.33
3. 1 Adult + 2 Childs: 69.33
4. 2 Adults: 59
5. 1 Adult + 1 Child: 59

I tried all possibilitys of filters i could image. The problem is, that a filter counts with 2 OR MORE adults – or – 2 OR MORE children.

Is there a way that i can say “if there are -2- Persons extra charge is 0.
Now the calculation counts: “If there are 2 or more Persons.

I reached to make everything working: except 1 Adult + 1 Child =59.

I hope you can help me with a solution, and i hope this is understandable.
I had also my problems with understanding the customers requirements.

Thanks in advance