Probability Rules Rap

Music and lyrics © 2005, 2013 Lawrence Mark Lesser

I'm a stat rapper, call me 50 perCENT!
Gonna begin with a complement:
The chance somethin' happens and the chance it don't
Sums to 1 -- the sample-space whole!

If 2 events don't affect each other
The chance they happen is the product of the numbers
But if that ain't reality,
Then it's P(A|B) times P(B).

CHORUS: We know odds good in our likelihood!
We got ability in probability:
We know it's got so much utility!

If two events don't overlap,
Chance of at least one: you just add.
But overlap brings double count,
So subtract the overlap amount. (Repeat Chorus)