Flopping FH and quads

[RedSoxFan]

So total bad beat but interested in knowing odds of this event happening (1/xxxxxx hands).

4 handed game

1) Probability that exactly 2 players are dealt pocket pairs.
2) Assuming both see flop- probability one flops FH and other flops quads.
3) Probability the person with the FH loses his stack (I can answer this one- 100%)

I had AA and flop was A88. Thought I was good until the dude turned over 88.

Can you show your formulas so I can start to learn this stuff and wont have to keep asking you guys to answer my random questions. Thanks