Ranking as a 40 on an exam or test that you and 550 student took can be explained as being in the 13th percentile. This means that you ranked better than 12% of your class. For example, someone who ranked 95 got a better score than 94% of the class. Someone who ranked as a 2 got one of the lowest scores possible.
Hate to break it to ya ,but since its 40% out of 100% i think its a bad thing. Anything lower than 79% is considered a fail. Where i live a 40% is probably a 1 or 0. 1 is really bad. 0 is the WORST. Is that what u got on a test? well i feel bad for you.. Just. try with all u got next time.