Could I mine altcoins on my desktop in background to make just 20-40 dollars a month?

I am thinking this could be a way to get some btc pocket money instead of having to deal with exchanges and fees etc.

If it is such a small amount is that possible by mining alt coins while my computer is still running my IM projects?

I read a guy on here say in a reply he made nearly a dollar's worth in a day just running a program sporadically which makes it sound very faesible if that is true.

My hardware is amd 8 core, 16gb ram and geforce gtx 660. Any good?

My IM scripts probably…

Could I mine altcoins on my desktop in background to make just 20-40 dollars a month?