Given: the probability of passing a Photography class is 75% and the probability of passing a Economics class is 65%. The probability of passing at least one test is 85%. The question asks for the probability of passing exactly one test.

I tried using binomial probability formula, but that one doesn't work because it uses the success and failure of just one event, not two...

Any help would be appreciated...

And btw, the answer to that is 60%... I just don't know how to get to that percentage...