#1 Thought experiment - "The Trolley Problem"

[Athene]

I don't "slink away in safety", bennyboy. I'm a nurse and volunteer EMT...in real life.
I've put my ass on the line more times than I can count; I'm well aware of what it takes to save a life.

So, you can get off your f*cking high horse at any moment.
Thanks.

Okay, great.  So you are a person of action.  Why, then, would you take a position of inaction causing the deaths of 5 innocent people?  I'd think that a nurse would be so horrified at killing 5 people that she'd instinctively turn away from them.  And I think that's the difference in our positions-- you are worried about who you'd turn TOWARD than who you might be able to turn AWAY FROM.

*sigh* One more time, then.

I would NOT be responsible for killing the five people. That would be due to a set of circumstances set into motion PRIOR to my arrival, that I was unable to prevent. Committing an act of cold-blooded murder towards an innocent person in order to rescue another or others does NOT constitute saving a life in my opinion; It's simply trading a life. Sure, five people could be "saved" if I murder one. So what? 

Even more people could be saved by plucking some poor schmuck off the street, murdering him, and harvesting his vital organs. Is that acceptable?  Would one be 'letting' potential recipients die or more dramatically put, be 'killing them' by simply leaving this man alone and allowing him to live out the fucking life he was given? I don't think so. 

What's the method for determining the worth of people's lives in these situations, anyway? Age? Net worth? Lifetime earning potential? Total number of dependents? 
Or is it just a matter of simple ratios?

If it should just boil down to numbers, then what is the magic number of people that warrants killing one person for the greater good? Is it five? A couple of hundred? 
Why not merely TWO, if doing the "right thing" in these scenarios simply comes down to a matter of math?