My only suggestion would be to not say I don't know. It would be "I'm not so familiar with XYZ, but here's how I'd solve that." Of course, if you can follow tha

My only suggestion would be to not say I don't know. It would be "I'm not so familiar with XYZ, but here's how I'd solve that." Of course, if you can follow that up with an example of a similar situation mitigates some of the risk. This would assume that it's not considered to be a core skill set. If it 's fringe skill you should still be in the running.