통과했어요 and 통과했습니다 both mean the same thing except that -습니다 is used for more formal situations (like the news). Why is it -습니다 here?
There is no reason here without any context. You'd had to assume the speaker is talking to his grandparents or something.
Tom made good points. The meanings are the same; the verb stem and conjugation are also the same. The difference is the formality. This item needs to be updated.
'통과했어요'랑 '통과했습니다' 중에 뭘 고를지 알 수가 있어야지...