I don't understand IF, THEN statments and also I don't get the Boolean operators OR, NOT, and AND.

I've read the turtorial about them but I just don't understand them and i don't get this:

A. !(1 || 0) ANSWER: 0

B. !(1 || 1 && 0) ANSWER: 0 (AND is evaluated before OR)

C. !((1 || 0) && 0) ANSWER: 1 (Parenthesis are useful

Can someone please help me out with this?