Flunked Amazon's Online assessment - how can I improve to prevent this in the future?

Hey guys. Just finished my online assessment like.. an hour ago. I managed 3/7 but watched the timer ticking down was very stressful. This obviously indicates that I need to brush up on my basics, whi

Hey guys. Just finished my online assessment like.. an hour ago. I managed 3/7 but watched the timer ticking down was very stressful. This obviously indicates that I need to brush up on my basics, which is disheartening. I know I've never been the smartest kid at all but I didn't think I'd be in the 'weeded out' group. What kind of resources should I be looking at and practicing so that I don't mess up like this again? Thanks guys.