Keep trying...
Don't give up yet, there is never just one way of solving a problem :wink:
OK Kizzap, if sw3 is operated it will stop the power reaching sw1 & 2 and so prevent them from working. R3 will energise and light bulb 3. R3 will also stop the power reaching R4's contacts: So far so good - But - if Sw4 is now operated ... ?
The switches here are wired as a kind of priority encoder - only the highest numbered switch can operate its relay, the relay contacts have a 'lowest takes priority' circuit - could these two elements be used to better effect :?: