Question 3
The answer to 3.a:
This is some of the tough stuff in this class and in CSS overall. You have to determine which style declarations apply to the markup directly and by inheritance. It's essentially an exercise in "working" the cascade.
Here are the style declarations that apply to the "Three important things to remember." paragraph:
font-style: normal; (inherited from body rule)
font-variant: small-caps; (inherited from body rule)
font-size: 12px; (inherited from body rule)
line-height: 16px; (inherited from body rule)
font-family: arial, sans-serif; (inherited from div#main rule)
font-weight: bold; (from p rule - direct match)
background: yellow; (from p rule - direct match)
color: red; (from div#main > p rule - direct match)
Note that the color: red; declaration applies (from the div#main > p rule) because that selector is more specific than the p selector (where the color is declared to be black).