[xenihn]

I don't see how this invalidates my original point, can you expand on your argument?

[usrbinbash]

What's the prerequisite for getting good at these questions? Practice and Memorizing.

What resource is required to do that? Time.

What resource is in short supply to the Philly single mom?

[xenihn]

Ok, so which comparatively-paying job is a better choice for her then?