Signing before Encryption and Signing after Encryption

[shyaam () gmail com]

Hello All,
I was asked a question in an interview. I would like to know more about this. I am sorry if it is really basic question.

What are the tradeoffs between Signing before Encryption and Signing after Encryption? Please do let me know on either 
case when you use a Symmetric Key and an Asymmetric key. 

I am sure that this is a very basic question. I appologize again.

Kind Regards,
Shyaam

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