Last Exam Day

Today was my last exam day, starring my physics test. It actually went pretty well, and I had no problems with any of the questions except for the last one (I couldn't remember formulas for calculating dosage equivalent). So what I did was just multiply all the data that was given to me and wrote that down. Such an answer is of course horribly wrong, but what do you do?

From now onto the final exams (in The Netherlands we have school exams given throughout the last three years and country-wide exams given in one week or so) Is about a month, and there's basically nothing in between. So Three weeks of pure relaxation. Except for the studying, of course. I guess that's important.