greek life questions

Hi guys,

I know PNMs shouldn't be on the site and go in fresh but I'm here anyways. I have a couple questions and would love it if someone could share their insights.
1. How much time would I need to commit to a sorority on a weekly basis?
2. What are the benefits of joining a "top" sorority other than perceived status?
3. It seems like a ton of girls drop out before graduation and pledge classes dwindle to a fraction of their original size. Why is this?
4. How competitive is rushing? Do most girls who rush end up getting a bid?
5. What does it mean to be number one for rush? I've heard girl bragging about rushing number one ( not from ucla but I'm curious)?
Thanks