A mistake you understand is worth more than three lucky guesses.
CREATIVITY
CREATIVITY
Getting a right answer you cannot account for leaves you exactly where you started, since you have no idea what to repeat. An error you have traced gives you a working part of the machine: you know which step bent, and why, and what it will look like next time it tries to happen. Understanding is what turns an event into something you own.
On your next returned test, spend the time on wrong answers rather than counting the right ones. For each, write one line saying what you did and what you should have done. That page is worth more at revision time than any summary.
Which lucky right answer are you secretly unsure about?
Free, with nothing to buy inside it.