multiple if conditions

multiple if conditions

Hi,

I´m new user and I would like to know how to combine multiple if conditions. For example:

I have two fields: -Survey- and -Projeto-. I have another field named -Percentual-.

If Survey is checked as "Done" - The Field Percentual have to show "50", so I did the following formula:

  1. if(Survey="Done", 50,0)

I did another formula: 

  1. if((Survey="Done") && (Projeto="Done"), 100,0))

Each formula works good whithout the other, but I want both formulas work together.

I tried this (didn´t work): 

  1. if(Survey="Done", 50,0) and if((Survey="Done") && (Projeto="Done"), 100,0))

  3. if(Survey="Done", 50,0) or if((Survey="Done") && (Projeto="Done"), 100,0))

Thanks in advance,

Regards from Brazil,

André