/sci/ - Science & Math

It depends.

Some students don't try, some students try very hard. Often it may happen that how much they try bears no relation with the performance of the tests because everyone's human and the effect personal problems have upon students affects greatly their performance. I've met very smart students that suffered depression, and they would do below average without medication; there are also smart students with family problems, smart students with social problems, etc...
The conditions in which a student live are almost the most important part when it come to doing good in your studies - you can't focus if your personal life is falling apart, if you don't have a quiet place on your own and so forth.

I do feel bad if a have to fail a student who is willing to learn and do good, but there are other things of which he has to take care of. We don't take these things in consideration in tests, if you are below the minimum score, you fail and that's it.