Argh!!! I'm freaking out 6 hours before my CAT midterm!!!

In my last-ditch attempt to mug for CAT, I tried 2 'test-prep' examples that my prof put up. BAD BAD mistake!!! I end up getting more lost! I really hope the test later won't be like that! I shall go sleep soon... But first.. I need to solve 1 last puestion on probability.. Arghz!!!!