logical negation training? (! used in algebraic expressions) Please Help!

I recently went to take a placement exam at my local college and was hit with questions about finding the solutions to problems using logical negation with ! as an operator placed in front of an expression. From what I understand it is a tool used in computer programming, where !A is true and only true if A is false, but I have no idea how to solve these problems, and cannot find videos on Khan related to it. Please! Can someone direct me to where I can learn about this, so I may improve my score on the test and get placed into a higher level of math?