In England we would say"I did well in the exam", definitely not " on the exam"
"I did good on the test" was marked wrong because it was supposed to be "well" not "good"?
No because you´re using passive voice in that sentence and this is active voice. I<-- the person, has the action, not the exam/ the object.
Yeah my Australian friend asks me all the time ¨How did you go?¨ and (we´re English teachers) I´m like BAHH your grammar is wrong! But I guess it´s just Australian 0:P hehe
Also one does not go an exam but does an exam. You have to use the verb to be, not to go.