[填空题]
Jennifer is about to /b2i +, svyn.fxo5 axba7el xd);*oxp take three exams in order: Mathematics, Chemistry and Biology. Based on what she has learned and practiced, sadx)p;* eo7 lxhe estimates that the probabilities that she will pass Mathematics, Chemistry and Biology exams are 0.8,0.6 and 0.7 , respectively. Assuming that the probability of Jenifer being passing an exam is independent of the others, find the probability that
1. she will pass all three exams;
2. she will pass only one of the exams;
3. she will pass the last two exams given that she doesn't pass the first exam;
4. she will pass at least one exam.
