Entrance Exam Season

I brought my son to UP Diliman today. He was scheduled to take the UPCAT. He was a bit worried and didn't have enough confidence. I just told him to do his best. It was a 4-hour examination, and he said it was very hard. He left items he didn't know, no room for guessing he says. I asked him if he was sure about his answers, and he said he was 90 percent sure. Thing is he left a lot of items blank too, so I don't really know his chance of passing. If you ask me how come he left a lot of items blank, it's because it's right minus wrong. No wild guesses here, only educated guesses, he says. I am still hoping though that he makes it, who knows, right?